Novavax (NVAX) 10-K 28 Feb 22 2021 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 21, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-26770
Entity Registrant Name	NOVAVAX, INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-2816046
Entity Address, Address Line One	21 Firstfield Road,
Entity Address, City or Town	Gaithersburg,
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20878
City Area Code	(240)
Local Phone Number	268-2000
Title of 12(b) Security	Common Stock, Par Value $0.01 per share
Trading Symbol	NVAX
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 15,697,000,000
Entity Common Stock, Shares Outstanding		76,282,986
Documents Incorporated by Reference	Documents incorporated by reference: Portions of the Registrant’s Definitive Proxy Statement to be filed no later than 120 days after the fiscal year ended December 31, 2021 in connection with the Registrant’s 2020 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent indicated herein.
Entity Central Index Key	0001000694
Document Fiscal Year Focus	2021
Amendment Flag	false
Document Fiscal Period Focus	FY

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Tysons, Virginia
Auditor Firm ID	42

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 1,515,116	$ 553,398
Marketable securities	0	157,649
Restricted cash	11,490	93,880
Accounts receivable	454,993	262,012
Prepaid expenses and other current assets	173,520	181,264
Total current assets	2,155,119	1,248,203
Property and equipment, net	228,696	179,954
Intangible assets, net	4,770	5,725
Goodwill	131,479	135,379
Other non-current assets	56,689	13,218
Total assets	2,576,753	1,582,479
Current liabilities:
Accounts payable	127,050	54,332
Accrued expenses	673,731	137,390
Deferred revenue	1,422,944	273,228
Current portion of finance lease liabilities	130,533	105,862
Other current liabilities	36,061	8,860
Total current liabilities	2,390,319	579,672
Deferred revenue	172,528	0
Convertible notes payable	323,458	322,035
Non-current finance lease liabilities	0	40,083
Other non-current liabilities	42,121	13,480
Total liabilities	2,928,426	955,270
Commitments and contingencies
Preferred stock, $0.01 par value, 2,000,000 shares authorized at December 31, 2021 and 2020; no shares issued and outstanding at December 31, 2021 and 2020	0	0
Stockholders’ equity (deficit):
Common stock, $0.01 par value, 600,000,000 shares authorized at December 31, 2021 and 2020; and 76,433,151 shares issued and 75,841,171 shares outstanding at December 31, 2021 and 71,350,365 shares issued and 70,953,739 shares outstanding at December 31, 2020	764	714
Additional paid-in capital	3,351,967	2,535,476
Accumulated deficit	(3,617,950)	(1,874,199)
Treasury stock, 591,980 shares, cost basis at December 31, 2021 and 396,626 shares, cost basis at December 31, 2020	(85,101)	(41,806)
Accumulated other comprehensive income (loss)	(1,353)	7,024
Total stockholders’ equity (deficit)	(351,673)	627,209
Total liabilities and stockholders’ equity (deficit)	$ 2,576,753	$ 1,582,479

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par or stated value per share (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value per share (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Common stock, shares issued (in shares)	76,433,151	71,350,365
Common stock, shares outstanding (in shares)	75,841,171	70,953,739
Treasury stock, shares (in shares)	591,980	396,626

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue:
Revenues	$ 1,146,290	$ 475,598	$ 18,662
Expenses:
Research and development	2,534,508	747,027	113,842
Gain on sale of assets	0	0	(9,016)
General and administrative	298,358	145,290	34,417
Total expenses	2,832,866	892,317	139,243
Loss from operations	(1,686,576)	(416,719)	(120,581)
Other income (expense):
Investment income	1,364	1,014	1,512
Interest expense	(21,127)	(15,145)	(13,612)
Other income (expense)	(8,197)	12,591	(13)
Loss before income tax expense	(1,714,536)	(418,259)	(132,694)
Income tax expense	29,215	0	0
Net loss	$ (1,743,751)	$ (418,259)	$ (132,694)
Earnings per share, basic (USD per share)	$ (23.44)	$ (7.27)	$ (5.51)
Earnings per share, diluted (USD per share)	$ (23.44)	$ (7.27)	$ (5.51)
Weighted average number of shares outstanding, diluted (in shares)	74,400	57,554	24,100
Weighted average number of shares outstanding, basic (in shares)	74,400	57,554	24,100
Grants
Revenue:
Revenues	$ 948,709	$ 453,210	$ 15,937
Royalties and other
Revenue:
Revenues	$ 197,581	$ 22,388	$ 2,725

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (1,743,751)	$ (418,259)	$ (132,694)
Other comprehensive income (loss):
Net unrealized gains (losses) on marketable securities available-for-sale, net of reclassifications	(9)	9	5
Foreign currency translation adjustment	(8,368)	19,523	(1,322)
Other comprehensive income (loss)	(8,377)	19,532	(1,317)
Comprehensive loss	$ (1,752,128)	$ (398,727)	$ (134,011)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance beginning (in shares) at Dec. 31, 2018		19,245,302
Balance beginning at Dec. 31, 2018	$ (167,935)	$ 192	$ 1,144,621	$ (1,299,107)	$ (2,450)	$ (11,191)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	17,048		17,048
Stock issued under incentive programs (in shares)		173,873
Stock issued under incentive programs	992	$ 2	1,122		(132)
Fractional shares purchased in stock split	(1)				(1)
Issuance of common stock, net of issuance costs (in shares)		12,980,177
Issuance of common stock, net of issuance costs	97,890	$ 130	97,760
Unrealized gain on marketable securities	5					5
Foreign currency translation adjustment	(1,322)					(1,322)
Net loss	(132,694)			(132,694)
Balance ending (in shares) at Dec. 31, 2019		32,399,352
Balance ending at Dec. 31, 2019	(186,017)	$ 324	1,260,551	(1,431,801)	(2,583)	(12,508)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock beneficial conversion feature	0		24,139	(24,139)
Conversion of preferred stock (in shares)		4,388,850
Conversion of preferred stock	199,822	$ 44	199,778
Stock-based compensation	128,035		128,035
Stock issued under incentive programs (in shares)		2,168,725
Stock issued under incentive programs	5,246	$ 22	44,447		(39,223)
Issuance of common stock, net of issuance costs (in shares)		32,393,438
Issuance of common stock, net of issuance costs	878,850	$ 324	878,526
Unrealized gain on marketable securities	9					9
Foreign currency translation adjustment	19,523					19,523
Net loss	(418,259)			(418,259)
Balance ending (in shares) at Dec. 31, 2020		71,350,365
Balance ending at Dec. 31, 2020	627,209	$ 714	2,535,476	(1,874,199)	(41,806)	7,024
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	183,626		183,626
Stock issued under incentive programs (in shares)		2,503,819
Stock issued under incentive programs	24,761	$ 24	68,032		(43,295)
Issuance of common stock, net of issuance costs (in shares)		2,578,967
Issuance of common stock, net of issuance costs	564,859	$ 26	564,833
Unrealized gain on marketable securities	(9)					(9)
Foreign currency translation adjustment	(8,368)					(8,368)
Net loss	(1,743,751)			(1,743,751)
Balance ending (in shares) at Dec. 31, 2021		76,433,151
Balance ending at Dec. 31, 2021	$ (351,673)	$ 764	$ 3,351,967	$ (3,617,950)	$ (85,101)	$ (1,353)

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' (DEFICIT) EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Issuance of common stock, issuance costs	$ 7,292	$ 11,416	$ 1,655

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Net loss	$ (1,743,751)	$ (418,259)	$ (132,694)
Reconciliation of net loss to net cash used in operating activities:
Depreciation and amortization	12,661	4,885	5,676
Gain on sale of assets	0	0	(9,016)
Right-of-use assets expensed	144,433	245,861	0
Non-cash stock-based compensation	183,626	128,035	17,048
Other items, net	(7,641)	(15,080)	6,381
Changes in operating assets and liabilities:
Accounts receivable, prepaid expenses, and other assets	(192,265)	(422,689)	(4,202)
Accounts payable and accrued expenses	600,326	163,161	(11,485)
Deferred revenue	1,325,557	271,545	(8,331)
Net cash provided by (used in) operating activities	322,946	(42,541)	(136,623)
Investing Activities:
Capital expenditures	(57,486)	(54,622)	(1,857)
Acquisition of Novavax CZ, net of cash acquired	0	(165,516)	0
Proceeds from sale of assets	0	0	18,333
Purchases of marketable securities	(2,167)	(363,202)	(17,484)
Proceeds from maturities of marketable securities	159,807	205,562	39,500
Net cash provided by (used in) investing activities	100,154	(377,778)	38,492
Financing Activities:
Proceeds from issuance of preferred stock	0	199,822	0
Net proceeds from sales of common stock	564,859	875,623	97,392
Net proceeds from the exercise of stock-based awards	24,761	5,382	992
Finance lease payments	(127,907)	(96,065)	0
Net cash provided by financing activities	461,713	984,762	98,384
Effect of exchange rate on cash, cash equivalents, and restricted cash	(5,292)	2,115	(32)
Net increase in cash, cash equivalents, and restricted cash	879,521	566,558	221
Cash, cash equivalents, and restricted cash at beginning of year	648,738	82,180	81,959
Cash, cash equivalents, and restricted cash at end of year	1,528,259	648,738	82,180
Supplemental disclosure of non-cash activities:
Sale of common stock under the Sales Agreement not settled at year-end	0	3,227	497
Capital expenditures included in accounts payable and accrued expenses	10,338	9,255	49
Right-of-use assets from new lease agreements	179,210	247,599	0
Supplemental disclosure of cash flow information:
Cash interest payments, net of amounts capitalized	19,428	13,705	12,188
Cash paid for income taxes	$ 12,606	$ 0	$ 0

Organization

Organization	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Novavax, Inc. (“Novavax,” and together with its wholly owned subsidiaries, including Novavax AB and Novavax CZ, the “Company”) is a biotechnology company that promotes improved global health through the discovery, development, and commercialization of innovative vaccines to prevent serious infectious diseases. The Company’s vaccine candidates, including both its coronavirus vaccine candidate, NVX-CoV2373, and its lead influenza vaccine candidate, NanoFlu, are genetically engineered, three-dimensional nanostructures of recombinant proteins critical to disease pathogenesis and may elicit differentiated immune responses, which may be more efficacious than naturally occurring immunity or traditional vaccines. NVX-CoV2373 and NanoFlu include the use of the Company's proprietary Matrix-M TM adjuvant. In December 2021, the Company was granted emergency use listing (“EUL”) for NVX-CoV2373 by the World Health Organization (“WHO”), to be marketed as Nuvaxovid TM in Europe and other markets and conditional marketing authorization for Nuvaxovid TM , which prequalifies NVX-CoV2373 as meeting WHO standards for quality, safety, and efficacy. The authorization follows the European Medicines Agency's (“EMA”) Committee for Medicinal Products for Human Use recommendation to authorize the vaccine and is applicable in all 27 European Union member states. During the fourth quarter of 2021, in partnership with Serum Institute of India Private Limited (“SIIPL”), the WHO granted EUL for NVX-CoV2373 to be manufactured and marketed by SIIPL as Covovax TM , the Drugs Controller General of India granted emergency use authorization (“EUA”) for NVX-CoV2373, which will be manufactured and marketed in India by SIIPL under the brand name Covovax TM , the National Agency of Drug and Food Control of the Republic of Indonesia, or Badan Pengawas Obat dan Makanan, granted EUA for NVX-CoV2373, to be manufactured and marketed in Indonesia by SIIPL under the brand name Covovax™, and the Philippine Food and Drug Administration granted EUA for NVX-CoV2373, to be manufactured and marketed in the Philippines by SIIPL under the brand name Covovax TM .

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements include the accounts of Novavax, Inc. and its wholly owned subsidiaries, including Novavax AB and Novavax CZ. All intercompany accounts and transactions have been eliminated in consolidation. Reclassifications Certain amounts reported in prior periods have been reclassified to conform to current period financial statement presentation. These reclassifications have no material effect on previously reported financial position, cash flows, or results of operations. The Company combined amounts previously reported as Government contracts revenue of $217.2 million and Grants revenue of $236.0 million for the year ended December 31, 2020, and Government contracts revenue of $7.5 million and Grants revenue of $8.4 million for the year ended December 31, 2019 into a single financial statement line item, Grants, in the consolidated statements of operations. Other revenue of $22.4 million for the year ended December 31, 2020, and $2.7 million for the year ended December 31, 2019 was reclassified to Royalties and other. Use of Estimates The preparation of the consolidated financial statements in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ materially from those estimates. Cash and Cash Equivalents Cash and cash equivalents consist of highly liquid investments with maturities of three months or less from the date of purchase. Cash and cash equivalents consist of the following (in thousands): December 31, 2021 2020 Cash $ 96,372 $ 122,312 Money market funds  361,822 96,116 Government-backed securities 266,250 44,250 Treasury securities — 44,052 Corporate debt securities 790,672 246,668 Cash and cash equivalents $ 1,515,116 $ 553,398 Cash equivalents are recorded at cost, which approximate fair value due to their short-term nature. Marketable Securities Marketable securities consist of debt securities with maturities greater than three months from the date of purchase that have historically included commercial paper, government-backed securities, treasury securities, corporate notes, and agency securities. Classification of marketable securities between current and non-current is dependent upon the maturity date at the balance sheet date taking into consideration the Company’s ability and intent to hold the investment to maturity. Interest and dividend income are recorded when earned and included in investment income in the consolidated statements of operations. Premiums and discounts, if any, on marketable securities are amortized or accreted to maturity and included in investment income in the consolidated statements of operations. The specific identification method is used in computing realized gains and losses on the sale of the Company’s securities. The Company classifies its marketable securities with readily determinable fair values as “available-for-sale.” Investments in securities that are classified as available-for-sale are measured at fair market value in the consolidated balance sheets, and unrealized gains and losses on marketable securities are reported as a separate component of stockholders’ equity (deficit) until realized. Marketable securities are evaluated periodically to determine whether a decline in value is “other-than-temporary.” The term “other-than-temporary” is not intended to indicate a permanent decline in value. Rather, it means that the prospects for a near term recovery of value are not necessarily favorable, or that there is a lack of evidence to support fair values equal to, or greater than, the carrying value of the security. Management reviews criteria, such as the magnitude and duration of the decline, as well as the Company’s ability to hold the securities, including whether the Company will be required to sell a security prior to recovery of its amortized cost basis, the investment issuer’s financial condition and business outlook to predict whether the loss in value is other-than-temporary. If a decline in value is determined to be other-than-temporary, the value of the security is reduced and the impairment is recorded as other income (expense) in the consolidated statements of operations. Fair Value Measurements The Company applies Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures (“ASC 820”), for financial and non-financial assets and liabilities. ASC 820 discusses valuation techniques, such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). The statement utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The following is a brief description of those three levels: • Level 1: Observable inputs such as quoted prices (unadjusted) in active markets for identical assets or liabilities. • Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. • Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions. Restricted Cash The Company’s current and non-current restricted cash includes payments received under the Coalition for Epidemic Preparedness Innovations (“CEPI”) funding agreements, payments received under the Bill & Melinda Gates Foundation (“BMGF”) grant agreements, and cash collateral accounts under letters of credit that serve as security deposits for certain facility leases. CEPI and BMGF funds become unrestricted as the Company incurs expenses for services performed under these agreements. As of December 31, 2021 and 2020, the restricted cash balances (both current and non-current) consisted primarily of $10.4 million and $92.4 million, respectively, of payments under the CEPI funding agreements. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported in the consolidated balance sheets that sum to the total of the same such amounts shown in the statement of cash flows (in thousands): December 31, 2021 2020 Cash and cash equivalents $ 1,515,116 $ 553,398 Restricted cash current 11,490 93,880 Restricted cash non-current (1) 1,653 1,460 Cash, cash equivalents and restricted cash $ 1,528,259 $ 648,738 (1) Classified as Other non-current assets as of December 31, 2021 and 2020 Accounts Receivable The Company recognizes amounts due from customers as accounts receivable when its right to payment is unconditional. The Company has evaluated outstanding receivables to assess collectability, with consideration given to economic conditions, the aging of receivables, and customer-specific risks. There was no allowance for doubtful accounts as of December 31, 2021, and 2020. There was no bad debt expense for the years ended December 31, 2021, 2020 or 2019. Concentration of Credit Risk Financial instruments expose the Company to concentration of credit risk and consist primarily of cash and cash equivalents and marketable securities. The Company’s investment policy limits investments to certain types of instruments, including asset-backed securities, high-grade corporate debt securities, and money market funds, places restrictions on maturities and concentrations in certain industries and requires the Company to maintain a certain level of liquidity. At times, the Company maintains cash balances in financial institutions, which may exceed federally insured limits. The Company has not experienced any losses relating to such accounts and believes it is not exposed to a significant credit risk on its cash and cash equivalents. The Company's accounts receivable arise from revenue arrangements with customers in different countries. The Company's revenue is primarily due to grants made by government-sponsored and private organizations, as well as royalties from our collaboration and license partners. The following entities accounted for more than 10% of total revenue or accounts receivable for the periods presented: Percentage of Revenue Percentage of Accounts Receivable as of December 31, 2021 2020 2019 2021 2020 U.S. government (a) 71 % 46 % 40 % * 78 % CEPI 12 % 47 % * * * BMGF * * 45 % * * SK bioscience, Co., Ltd. 14 % * * * * Gavi, the Vaccine Alliance * * * 77 % * Government of New Zealand * * * * 17 % *Amounts represent less than 10% (a) Including U.S. government partnership formerly known as Operation Warp Speed, Department of Defense, and Biomedical Advanced Research and Development Authority Pre-Launch Inventory Prior to initial regulatory authorizations for its product candidates, the Company expenses costs relating to raw materials and inventory production as research and development expenses in the consolidated statements of operations, in the period incurred. The Company capitalizes the costs of production as inventory when regulatory authorization and subsequent commercialization are considered probable and the Company expects to realize future economic benefit from the sales of the product candidate. Upon the authorization of distribution and use of NVX-CoV2373 following regulatory authorizations by EMA and the WHO in December 2021, the Company began to capitalize inventory costs associated with the related supply of NVX-CoV2373, as it was determined that inventory costs subsequently incurred had a probable future economic benefit. Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. and are depreciated using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance costs are expensed as incurred. The estimated useful lives of property and equipment are described below: Useful Life Buildings 25 years Machinery and equipment 5 - 7 years Computer hardware 3 years Leasehold improvements Shorter of useful life or remaining term of the lease Lease Accounting The Company enters into manufacturing supply agreements with contract manufacturing organizations (“CMO”) and contract development and manufacturing organizations (“CDMO”) to manufacture its vaccine candidates. Certain of these manufacturing supply agreements include the use of identified manufacturing facilities and equipment that are controlled by the Company and for which the Company obtains substantially all the output and may qualify as an embedded lease. The Company treats manufacturing supply agreements that contain a lease as lease arrangements in their entirety. The evaluation of leases that are embedded in the Company’s CMO and CDMO agreements is complex and requires judgment in determining whether the contract, either explicitly or implicitly, is for the use of an identified asset and the Company has the right to direct the use of, and obtain substantially all of the benefit from, the identified asset which generally, is the use of a portion of the manufacturing facility of the CMO or CDMO, whether the Company has the right to direct the use of, and obtain substantially all of the benefit from, the identified asset, the term of the lease, and the fixed lease payments under the contract. Depending on the contract, the lease commencement date, defined as the date on which the lessor makes the underlying asset available for use by the lessee and is the date on which the Company is required to accrue lease expenses, may be different than the inception date of the contract. The Company determines the non-cancellable lease term of its embedded leases based on the impact of certain expected milestones on its option to terminate the lease where it is reasonably certain to not exercise that option. The Company evaluates changes to the terms and conditions of a lease contract to determine if they result in a new lease or a modification of an existing lease. For lease modifications, the Company remeasures and reallocates the remaining consideration in the contract and reassesses the lease classification at the effective date of the modification. Leases are classified as either operating or finance leases based on the economic substance of the agreement. The Company also enters into non-cancelable lease agreements for facilities and certain equipment. For leases that have a lease term of more than 12 months at the lease commencement date, the Company recognizes lease liabilities, which represent the Company’s obligation to make lease payments arising from the lease, and corresponding right-of-use (“ROU”) assets, which represent the right to use an underlying asset for the lease term, based on the present value of the fixed future payments over the lease term. The Company calculates the present value of future payments using the discount rate implicit in the lease, if available, or the Company’s incremental borrowing rate. For all leases that have a lease term of 12 months or less at the commencement date (referred to as “short-term” leases), the Company has elected to apply the practical expedient in ASC Topic 842, Leases (“ASC 842”), to not recognize a lease liability or ROU asset but, instead, recognize lease payments as an expense on a straight-line basis over the lease term and variable lease payments that do not depend on an index or rate as an expense in the period in which the variable lease costs are incurred based on performance or usage in accordance with contractual agreements. In determining the lease period, the Company evaluates facts and circumstances that could affect the period over which it is reasonably certain to use the underlying asset while taking into consideration the non-cancelable period over which it has the right to use the underlying asset and any option period to extend or terminate the lease if it is reasonably certain to exercise the option. The Company re-evaluates short-term leases that are modified and if they no longer meet the requirements to be treated as a short-term lease, recognizes and measures the lease liability and ROU asset as if the date of the modification is the lease commencement date. For short-term leases that are modified and continue to meet the requirements to be treated as a short-term lease, the Company remeasures the fixed lease payments under the modified lease and recognize lease payments as an expense on a straight-line basis over the modified lease term. For operating leases, the Company recognizes lease expense related to fixed payments on a straight-line basis over the lease term and lease expense related to variable payments as incurred based on performance or usage in accordance with the contractual agreements. For finance leases, the Company recognizes the amortization of the ROU asset over the shorter of the lease term or useful life of the underlying asset. The Company expenses ROU assets acquired for research and development activities under ASC Topic 730, Research and Development , if they do not have an alternative future use, in research and development projects or otherwise. The Company uses significant assumptions and judgment in evaluating its lease contracts and other agreements under ASC 842, including the determination of whether an agreement is or contains a lease, whether a change in the terms and conditions of a lease contract represent a new or modified lease, whether a lease represents an operating or finance lease, the discount rate used to determine the present value of lease obligations, and the term of a lease embedded in its manufacturing supply agreements. Intangible Assets The Company’s intangible assets include proprietary adjuvant technology and collaboration agreements, which were measured at the estimated fair values as of their acquisition dates. Amortization expense for intangible assets is recorded on a straight-line basis over the expected useful lives of the assets, ranging from 7 years to 20 years. Impairment of Long-Lived Assets Long-lived assets, including property and equipment and finite-lived intangible and right-of-use assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable based on the criteria for accounting for the impairment or disposal of long-lived assets under ASC Topic 360, Property, Plant and Equipment. The Company calculates the estimated fair value of a long-lived asset (group) using the income approach. Impairment losses are recognized when the sum of expected future cash flows is less than the assets’ (group’s) carrying value. Goodwill Goodwill is subject to impairment tests annually or more frequently should indicators of impairment arise. The Company has determined that, because its only business is the development of recombinant vaccines, it operates as a single operating segment and has one reporting unit. The Company primarily utilizes the market approach and, if considered necessary, the income approach to determine if it has an impairment of its goodwill. The market approach is based on market value of invested capital. To ensure that the Company’s capital stock is the appropriate measurement of fair value, the Company considers factors such as its trading volume, diversity of investors, and analyst coverage. If considered necessary, the income approach is used to corroborate the results of the market approach. Goodwill impairment may exist if the carrying value of the reporting unit exceeds its estimated fair value. If the carrying value of the reporting unit exceeds its fair value, step two of the impairment analysis is performed. In step two of the analysis, an impairment loss is recorded equal to the excess of the carrying value of the reporting unit’s goodwill over its implied fair value, should such a circumstance arise. At October 1, 2021 and 2020, the fair value of the Company’s single reporting unit was substantially higher than its carrying value, resulting in no impairment to goodwill as of October 1, 2021 and 2020. Revenue Recognition At contract inception, the Company analyzes its revenue arrangements to determine the appropriate accounting under U.S. GAAP. Currently, the Company’s revenue arrangements represent customer contracts within the scope of ASC Topic 606, Revenue from Contracts with Customers (Topic 606) (“ASC 606”), or are subject to the contribution guidance in ASC Topic 958-605, Not-for-Profit Entities – Revenue Recognition (“ASC 958-605”), which applies to business entities that receive contributions within the scope of ASC 958-605. The Company recognizes revenue from arrangements within the scope of ASC 606 following the five-step model: (i) identify the contract(s) with a customer; (ii) identify the performance obligation(s) in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligation(s) in the contract; and (v) recognize revenue when (or as) it satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration it is entitled to in exchange for the goods or services it transfers to its customer. The Company recognizes contribution revenue within the scope of ASC 958-605 when the funder-imposed conditions have been substantially met. Contributions are recorded as deferred revenue until the period in which research and development activities are performed that satisfy the funder-imposed conditions. Grants Grant revenue includes both revenue from government contracts and grants from organizations such as CEPI. The Company performs research and development under government funding, grant, license, and clinical development agreements. The revenue primarily consists of funding under U.S. government contracts and other arrangements to advance the clinical development and manufacturing of NVX-CoV2373. The Company’s U.S. government contracts are with the U.S. Department of Defense (the “DoD”) and the U.S. government partnership formerly known as Operation Warp Speed (“OWS”) (see Note 12). Other funding arrangements primarily include a grant and forgivable loan funding from CEPI (see Note 12). Under the U.S. government contracts, the Company is entitled to receive funding on a cost-reimbursable or cost-reimbursable-plus-fixed-fee basis, to support certain activities related to the development, manufacture, and delivery of NVX-CoV2373 to the U.S. government. The Company analyzed these contracts and determined that they are within the scope of ASC 606. The obligations under each of the contracts are not distinct in the context of the contract as they are highly interdependent or interrelated and, as such, they are accounted for as a single performance obligation. The transaction price under these arrangements is the consideration the Company is expecting to receive and consists of the funded contract amount and the unfunded variable amount to the extent that it is probable that a significant reversal of revenue will not occur. The Company recognizes revenue for these contracts over time as the Company transfers control over the goods and services and satisfies the performance obligation. The Company measures progress toward satisfaction of the performance obligation using an Estimate-at-Completion (“EAC”) process, which is a cost-based input method that reviews and monitors the progress towards the completion of the Company’s performance obligation. Under this process, management considers the costs that have been incurred to-date, as well as projections to completion using various inputs and assumptions, including, but not limited to, progress towards completion, labor costs and level of effort, material and subcontractor costs, indirect administrative costs, and other identified risks. Estimating the total allowable cost at completion of the performance obligation under a contract is subjective and requires the Company to make assumptions about future activity and cost drivers. Changes in these estimates can occur for a variety of reasons and, if significant, may impact the timing of revenue and fee recognition on the Company’s contracts. Allowable contract costs include direct costs incurred on the contract and indirect costs that are applied in the form of rates to the direct costs. Progress billings under the contracts are initially based on provisional indirect billing rates, agreed upon between the Company and the U.S. government. These indirect rates are subject to review on an annual basis. The Company records the impact of changes in the indirect billing rates in the period when such changes are identified. These changes reflect the difference between actual indirect costs incurred compared to the estimated amounts used to determine the provisional indirect billing rates agreed upon with the U.S. government. The Company recognizes revenue on the U.S government contracts based on reimbursable allowable contract costs incurred in the period up to the transaction price. For cost-reimbursable-plus-fixed-fee contracts, the Company recognizes the fixed-fee based on the proportion of reimbursable contract costs incurred to total estimated allowable contract costs expected to be incurred on completion of the underlying performance obligation as determined under the EAC process. The Company recognizes changes in estimates related to the EAC process in the period when such changes are made on a cumulative catch-up basis. The Company includes the transaction price comprising both funded and unfunded portions of customer contracts in this estimate. The Company’s other funding agreements currently include funding from CEPI in the form of a grant (“CEPI Grant Funding”) and one or more forgivable no interest term loans (“CEPI Forgivable Loan Funding”). Under the Company’s grant funding arrangements, currently including the CEPI and BMGF arrangements, the Company is primarily entitled to reimbursement for costs that support development related activities of NVX-CoV2373. The Company analyzed these other funding arrangements and determined that they are not within the scope of ASC 606 as they do not provide a direct economic benefit to the grantor. Payments received under the grant funding arrangements are considered conditional contributions under the scope of ASC 958-605 and are recorded as deferred revenue until the period in which such research and development activities are actually performed in a manner that satisfies the funder-imposed conditions. Payments received under the CEPI Forgivable Loan Funding agreement are only repayable if the proceeds of sales to one or more third parties of NVX-CoV2373 cover the Company’s costs of manufacturing such vaccine candidate, not including manufacturing costs funded by CEPI. As the financial risk remains with CEPI, the Company determined that the use of the funds from the CEPI agreement is outside the scope of ASC Topic 470, Debt . The research and development risk was considered substantive, such that it was not probable that the development would be successful at the inception of the contract. Therefore, the Company concluded that ASC 730 was considered applicable and most appropriate. Given the financial risk associated with the research and development activities lies with CEPI because repayment of any funds provided by CEPI depends solely on the results of the research and development activities having future economic benefit, the Company has accounted for the obligation under the CEPI Forgivable Loan Funding as a contract to perform research and development for others. The Company has determined that payments received under these agreements should be recorded as revenue under ASC 958-605 rather than a reduction to research and development expenses. This is consistent with the Company’s policy of presenting such amounts as revenue. In reaching this determination, the Company considered a number of factors, including whether it is principal under the arrangement, and whether the arrangement is significant to, and part of, the Company’s core operations. The Company will record revenue as it performs the contractual research and development services. Royalties and Other The Company also has various arrangements that include a right for a third party to use the Company's intellectual property as a functional license. These licensing arrangements include sales-based royalties, certain development and commercial milestone payments, and the sale of proprietary Matrix-M TM adjuvant. The license is deemed to be the predominant item to which the sales-based royalties or milestone payments relate. Because development milestone payments are contingent on the achievement of milestones, such as regulatory approvals, that are not within the Company or licensee's control, the payments are not considered probable of being achieved and are excluded from the transaction price until the milestone is achieved. The Company recognizes revenue when the development milestone is achieved. For arrangements that include sales-based royalties, including milestone payments based upon the achievement of a certain level of product sales, wherein the license is deemed to be the sole or predominant item, the Company recognizes revenue on the satisfaction (or partial satisfaction) of the performance obligation, which is when the related sales occur. The Company allocates the transaction price to each performance obligation based on a relative standalone selling price basis. It develops assumptions that require judgment to determine the standalone selling price for each performance obligation in consideration of applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer. Research and Development Expenses Research and development expenses include salaries, stock-based compensation, laboratory supplies, consultants and subcontractors, including external contract research organizations (“CROs”), CMOs, and CDMOs and other expenses associated with the Company’s process development, manufacturing, clinical, regulatory, and quality assurance activities for its clinical development programs. In addition, related indirect costs such as fringe benefits and overhead expenses are also included in research and development expenses. The Company estimates its research and development expense related to services performed under its contracts with external service providers based on an estimate of the level of service performed in the period. Research and development activities are expensed as incurred. Accrued Research and Development Expenses The Company accrues research and development expenses, including clinical trial-related expenses, as the services are performed, which may include estimates of those expenses incurred, but not invoiced. The Company uses information provided by third-party service providers and CROs, CMOs, and CDMOs invoices and internal estimates to determine the progress of work performed on the Company’s behalf. Assumptions based on clinical trial protocols, contracts, and participant enrollment data are also developed to determine and analyze these estimates and accruals. Stock-Based Compensation The Company accounts for stock-based compensation related to grants of stock options, stock appreciation rights, restricted stock awards, and purchases under the Company’s Employee Stock Purchase Plan, as amended and restated (the “ESPP”), at fair value. The Company recognizes compensation expense related to such awards on a straight-line basis over the requisite service period (generally the vesting period) of the equity awards, based on the award's fair value at the grant date. The requisite service period is typically one The expected term of stock options and stock appreciation rights granted is based on the Company’s historical option exercise experience and post-vesting forfeiture experience using the historical expected term from the vesting date, whereas the expected term for purchases under the ESPP is based on the purchase periods included in the offering. The expected volatility is determined using historical volatilities based on stock prices over a look-back period corresponding to the expected term. The risk-free interest rate is determined using the yield available for zero-coupon U.S. government issues with a remaining term equal to the expected term. The Company has never paid a dividend, and as such, the dividend yield is zero, and the Company does not intend to pay dividends in the foreseeable future. See Note 13 for a further discussion on stock-based compensation. Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Income Taxes . Under the liability method, deferred income taxes are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled. The effect of changes in tax rates on deferred tax assets and liabilities is recognized in income in the period such changes are enacted. A valuation allowance is established when necessary to reduce net deferred tax assets to the amount expected to be realized. Tax benefits associated with uncertain tax positions are recognized in the period in which one of the following conditions is satisfied: (1) the more likely than not recognition threshold is satisfied; (2) the position is ultimately settled through negotiation or litigation; or (3) the statute of limitations for the taxing authority to examine and challenge the position has expired. Tax benefits associated with an uncertain tax position are reversed in the period in which the more likely than not recognition threshold is no longer satisfied. The Company has historically generated significant federal, state, and foreign tax net operating losses, which may be subject to limitation in future periods. Management has fully reserve

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The Company had no marketable securities classified as available-for-sale as of December 31, 2021 as all of the Company's investments were in securities classified as cash and cash equivalents. Marketable securities classified as available-for-sale as of December 31, 2020 were comprised of (in thousands): December 31, 2020 Amortized Cost Gross Unrealized Gross Unrealized Losses Fair Value Treasury securities $ 10,038 $ — $ (2) $ 10,036 Corporate debt securities 127,003 13 (3) 127,013 Agency securities 20,599 1 — 20,600 Total $ 157,640 $ 14 $ (5) $ 157,649

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following table represents the estimated fair value of the Company’s financial assets and liabilities (in thousands): Fair Value at December 31, 2021 Fair Value at December 31, 2020 Assets Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Money market funds (1) $ 361,822 $ — $ — $ 96,116 $ — $ — Government-backed securities (1) — 266,250 — — 44,250 — Treasury securities (2) — — — — 54,088 — Corporate debt securities (3) — 790,672 — — 373,681 — Agency securities — — — — 20,600 — Total cash equivalents and marketable securities $ 361,822 $ 1,056,922 $ — $ 96,116 $ 492,619 $ — Liabilities Convertible notes payable $ — $ 447,509 $ — $ — $ 407,238 $ — (1) Classified as cash and cash equivalents as of December 31, 2021 and 2020 (see Note 2). (2) Includes $44,052 classified as cash and cash equivalents as of December 31, 2020 on the consolidated balance sheets. (3) Includes $790,672 and $246,668 classified as cash and cash equivalents as of December 31, 2021 and 2020, respectively, on the consolidated balance sheets. Fixed-income investments categorized as Level 2 are valued at the custodian bank by a third-party pricing vendor’s valuation models that use verifiable observable market data, such as interest rates and yield curves observable at commonly quoted intervals and credit spreads, bids provided by brokers or dealers, or quoted prices of securities with similar characteristics. Pricing of the Company’s Notes (as defined in Note 8) has been estimated using other observable inputs, including the price of the Company’s common stock, implied volatility, interest rates, and credit spreads among others. During the years ended December 31, 2021 and 2020, the Company did not have any transfers between Levels. The amount in the Company’s consolidated balance sheets for accounts payable and accrued expenses approximates its fair value due to its short-term nature.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	Intangible Assets and Goodwill Identifiable Intangible Assets Purchased intangible assets consisted of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Intangible Assets, Net Gross Carrying Amount Accumulated Amortization Intangible Assets, Net Finite-lived intangible assets: Proprietary adjuvant technology $ 8,239 $ (3,469) $ 4,770 $ 9,099 $ (3,374) $ 5,725 Collaboration agreements 3,722 (3,722) — 4,109 (4,109) — Total identifiable intangible assets $ 11,961 $ (7,191) $ 4,770 $ 13,208 $ (7,483) $ 5,725 Amortization expense for the years ended December 2021, 2020, and 2019 was $0.4 million, $0.6 million, and $0.7 million, respectively. Estimated amortization expense for existing intangible assets for each of the five succeeding years ending December 31 is as follows (in thousands): Year Amount 2022 $ 412 2023 412 2024 412 2025 412 2026 412 Goodwill The change in the carrying amounts of goodwill was as follows (in thousands): Year Ended December 31, 2021 2020 Beginning balance $ 135,379 $ 51,154 Goodwill resulting from the acquisition of Novavax CZ — 70,662 Currency translation adjustments (3,900) 13,563 Ending balance $ 131,479 $ 135,379

Acquisition of Novavax CZ

Acquisition of Novavax CZ	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Acquisition of Novavax CZ	Acquisition of Novavax CZ On May 27, 2020 (the “Acquisition Date”), the Company entered into a Share Purchase Agreement (the “Deed”) by and among Novavax AB, the Company’s wholly-owned Swedish subsidiary (the “Buyer”), and De Bilt Holdings B.V., Poonawalla Science Park B.V., and Bilthoven Biologicals B.V. (collectively, the “Sellers”) and, solely as guarantors, each of Serum International B.V. and the Company. Pursuant to the terms and conditions of the Deed, the Buyer acquired all the issued and outstanding shares of Novavax CZ (formerly, Praha Vaccines a.s.), a vaccine manufacturing company (the “Acquisition”). The assets of Novavax CZ acquired as part of the Acquisition include a biologics manufacturing facility and associated assets in Bohumil, Czech Republic and will be used by the Company to expand its manufacturing capacity. Allocation of Purchase Price to Assets Acquired and Liabilities Assumed The Company has accounted for the Acquisition as a business combination using the acquisition method of accounting, with the Company as the acquirer. The acquisition method requires the Company to record the assets acquired and liabilities assumed at fair value. The amount by which the purchase price exceeds the fair value of net assets acquired is recorded as goodwill. The Company completed the appraisal process necessary to assess the fair values of the assets acquired and liabilities assumed to determine the amount of goodwill to be recognized as of the Acquisition Date. The final determination of the fair value of all assets and liabilities was completed in 2020 and is presented in the table below. The table below summarizes the final allocation of the purchase price based upon the fair values of assets acquired and liabilities assumed (in thousands): May 27, 2020 Prepaid expense and other current assets $ 326 Property and equipment 96,739 Goodwill 70,662 Accounts payable (1,193) Accrued expenses (205) Other non-current liabilities (813) Purchase price, net of cash acquired $ 165,516 The fair value of the assets acquired and liabilities assumed was determined using market and cost valuation methodologies. The fair value measurements were based on significant unobservable inputs that were developed by the Company using publicly available information, market participant assumptions, and cost and development assumptions. Because of the use of significant unobservable inputs, the fair value measurements represent a Level 3 measurement as defined in ASC 820. The market approach is a valuation technique that uses prices and other relevant information generated by market transactions involving identical or comparable assets, liabilities, or a group of assets or liabilities. The cost approach estimates value by determining the current cost of replacing an asset with another of equivalent utility. The cost to replace a given asset reflects the estimated reproduction or replacement cost for the property, less an allowance for loss in value due to depreciation. The cost approach was the primary approach used to value fixed assets, including the real property. Fixed assets are depreciated on a straight-line basis over their expected remaining useful lives, ranging from four years to 25 years. The Company recorded $70.7 million in goodwill related to the Acquisition representing the purchase price that was in excess of the fair value of the assets acquired and liabilities assumed. The goodwill generated from the Acquisition is not expected to be deductible for U.S. federal income tax purposes. The goodwill recognized is attributable to intangible assets that do not qualify for separate recognition, such as the assembled workforce of Novavax CZ. Current assets and current liabilities were recorded at their contractual or historical acquisition amounts, which approximate their fair value. Impact to Financial Results for the Year Ended December 31, 2020 The results of operations from Novavax CZ have been included in the consolidated financial statements since the Acquisition Date. As a result, the consolidated financial results for the year ended December 31, 2020 does not reflect a full twelve months of Novavax CZ results. From the Acquisition Date through December 31, 2020, Novavax CZ did not recognize any revenue and recorded a net loss from operations of $11.3 million. The Company incurred approximately $2.7 million of costs related to the Acquisition in the year ended December 31, 2020, which are included within general and administrative expenses in the consolidated statements of operations. Supplemental Pro Forma Financial Information (Unaudited) The unaudited pro forma financial information below gives effect to the Acquisition as if it had occurred as of January 1, 2019. The pro forma financial information is presented for informational purposes only and is not necessarily indicative of the results of operations that would have been achieved had the Acquisition been consummated as of that time. The unaudited pro forma financial information combines the historical results of operations of the Company and Novavax CZ and reflects the application of certain pro forma adjustments (in thousands, except per share amounts): Year Ended December 31, 2020 2019 Revenue $ 475,598 $ 18,662 Net loss (419,896) (142,210) Basic and diluted net loss per share $ (7.04) $ (3.22) Pro forma adjustments include the recognition of depreciation expense based on the Acquisition Date fair value and remaining useful lives of Novavax CZ fixed assets (net of historical depreciation expense) and the elimination of costs related to the Acquisition, which are non-recurring in nature.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	Leases The Company has embedded leases related to multiple manufacturing supply agreements with CMOs and CDMOs to manufacture the Company’s COVID-19 vaccine candidate, NVX-CoV2373, as well as operating leases for its research and development and manufacturing facilities, corporate headquarters and offices, and certain equipment. During 2021 and 2020, the Company entered into various CMO and CDMO manufacturing supply agreements that include the use of identified manufacturing facilities and contain fixed or minimum commitments. The Company evaluated the agreements at inception and determined that certain of these arrangements contain an embedded lease under ASC 842 as it has the exclusive use of, and control over, a portion of the manufacturing facility and equipment of the supplier during the contractual term of the arrangement. The Company classified the CMO and CDMO arrangements as operating and finance leases based on the terms of the agreement. The Company recognized lease expense related to fixed payments for its short-term operating leases on a straight-line basis over the lease term and lease expense related to variable payments as incurred based on performance or usage in accordance with the contractual agreements. Additionally, during 2021, the Company amended its various CMO and CDMO agreements that modified existing embedded leases under ASC 842 as the Company continued to have the exclusive use of, and control over, a portion of manufacturing facilities and equipment of the supplier during the contractual term of the new arrangement. For leases that were previously determined to represent short-term embedded leases, the modifications did not result in a change in lease classification. During 2021 and 2020, the Company recognized ROU assets of $144.4 million and $245.9 million, respectively, for its finance leases and long-term operating related to leases embedded in CMO and CDMO manufacturing supply agreements. The Company expensed the ROU assets since they relate to research and development activities for the development of NVX-CoV2373 for which the Company does not have an alternative future use. During 2021, the Company entered into and extended various facility lease agreements related to research and development facilities and office space. During 2020, the Company entered into a lease agreement for the premises located at 700 Quince Orchard Road, Gaithersburg, Maryland ("700QO"). The lease is for approximately 170,000 square feet of space that the Company intends to use for manufacturing, research and development, and offices. The term of the lease is 15 years with options to extend the lease. The lease provides for an annual base rent of $5.8 million that is subject to future rent increases, and obligates the Company to pay building operating costs. The Company incurred $36.4 million in 2021 related to tenant improvement costs and anticipates that it will incur substantial additional tenant improvement costs, net of total landlord contribution of $30.6 million, through 2023 to bring the building to the condition necessary for its intended use. The Company is anticipated to occupy the premises in phases and occupied the third floor during the first quarter of 2022. As of December 31, 2021, the facility leases, excluding the 700QO lease, have expirations that range from approximately three The Company uses its incremental borrowing rate in determining its ROU assets and long-term lease obligations. The Company uses significant judgment and estimates, including the estimated value of the underlying leased asset and financial profile of comparable companies, to analyze the credit spread as of the lease inception date. Supplemental balance sheet information related to leases as of December 31, 2021 and 2020 was as follows (in thousands, except weighted-average remaining lease term and discount rate): December 31, Lease Assets and Liabilities Classification 2021 2020 Assets: ROU assets, operating, net Other non-current assets $ 40,123 $ 7,794 Liabilities: Current portion of operating lease liabilities Other current liabilities $ 30,983 $ 3,782 Current portion of finance lease liabilities Current portion of finance lease liabilities 130,533 105,862 Total current lease liabilities $ 161,516 $ 109,644 Non-current portion of operating lease liabilities Other non-current liabilities $ 39,116 $ 10,122 Non-current portion of finance lease liabilities Non-current finance lease liabilities — 40,083 Total non-current lease liabilities $ 39,116 $ 50,205 Weighted-average remaining lease term (years): Operating leases 5.0 4.5 Finance leases 3.7 4.7 Weighted-average discount rate: Operating leases 6.0% 13.8% Finance leases 5.2% 6.4% Lease expense for the operating and short-term leases for the years ended December 31, 2021 and 2020 was as follows (in thousands): Year Ended December 31, 2021 2020 Operating lease expense $ 37,027 $ 2,462 Short-term lease expense 468,210 66,805 Variable lease expense 116,435 4,854 Finance lease expense: ROU assets expensed $ 112,528 $ 242,009 Interest expense 7,241 3,097 Total finance lease expense $ 119,769 $ 245,106 Supplemental cash flow information related to leases for the year ended December 31, 2021 and 2020 was as follows (in thousands): Year Ended December 31, 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used in operating leases $ 203,991 $ 63,634 Operating cash flows used in finance leases 7,241 3,097 Financing cash flows used in finance leases 127,907 96,065 ROU assets obtained in exchange for operating lease obligations $ 66,682 $ 5,590 ROU assets obtained in exchange for finance lease obligations 112,528 242,009 As of December 31, 2021, maturities of lease liabilities were as follows (in thousands): Year Amount 2022 $ 166,244 2023 7,104 2024 7,238 2025 7,361 2026 7,344 Thereafter 19,186 Total minimum lease payments 214,477 Less: imputed interest (13,845) Total lease liabilities $ 200,632
Leases	Leases The Company has embedded leases related to multiple manufacturing supply agreements with CMOs and CDMOs to manufacture the Company’s COVID-19 vaccine candidate, NVX-CoV2373, as well as operating leases for its research and development and manufacturing facilities, corporate headquarters and offices, and certain equipment. During 2021 and 2020, the Company entered into various CMO and CDMO manufacturing supply agreements that include the use of identified manufacturing facilities and contain fixed or minimum commitments. The Company evaluated the agreements at inception and determined that certain of these arrangements contain an embedded lease under ASC 842 as it has the exclusive use of, and control over, a portion of the manufacturing facility and equipment of the supplier during the contractual term of the arrangement. The Company classified the CMO and CDMO arrangements as operating and finance leases based on the terms of the agreement. The Company recognized lease expense related to fixed payments for its short-term operating leases on a straight-line basis over the lease term and lease expense related to variable payments as incurred based on performance or usage in accordance with the contractual agreements. Additionally, during 2021, the Company amended its various CMO and CDMO agreements that modified existing embedded leases under ASC 842 as the Company continued to have the exclusive use of, and control over, a portion of manufacturing facilities and equipment of the supplier during the contractual term of the new arrangement. For leases that were previously determined to represent short-term embedded leases, the modifications did not result in a change in lease classification. During 2021 and 2020, the Company recognized ROU assets of $144.4 million and $245.9 million, respectively, for its finance leases and long-term operating related to leases embedded in CMO and CDMO manufacturing supply agreements. The Company expensed the ROU assets since they relate to research and development activities for the development of NVX-CoV2373 for which the Company does not have an alternative future use. During 2021, the Company entered into and extended various facility lease agreements related to research and development facilities and office space. During 2020, the Company entered into a lease agreement for the premises located at 700 Quince Orchard Road, Gaithersburg, Maryland ("700QO"). The lease is for approximately 170,000 square feet of space that the Company intends to use for manufacturing, research and development, and offices. The term of the lease is 15 years with options to extend the lease. The lease provides for an annual base rent of $5.8 million that is subject to future rent increases, and obligates the Company to pay building operating costs. The Company incurred $36.4 million in 2021 related to tenant improvement costs and anticipates that it will incur substantial additional tenant improvement costs, net of total landlord contribution of $30.6 million, through 2023 to bring the building to the condition necessary for its intended use. The Company is anticipated to occupy the premises in phases and occupied the third floor during the first quarter of 2022. As of December 31, 2021, the facility leases, excluding the 700QO lease, have expirations that range from approximately three The Company uses its incremental borrowing rate in determining its ROU assets and long-term lease obligations. The Company uses significant judgment and estimates, including the estimated value of the underlying leased asset and financial profile of comparable companies, to analyze the credit spread as of the lease inception date. Supplemental balance sheet information related to leases as of December 31, 2021 and 2020 was as follows (in thousands, except weighted-average remaining lease term and discount rate): December 31, Lease Assets and Liabilities Classification 2021 2020 Assets: ROU assets, operating, net Other non-current assets $ 40,123 $ 7,794 Liabilities: Current portion of operating lease liabilities Other current liabilities $ 30,983 $ 3,782 Current portion of finance lease liabilities Current portion of finance lease liabilities 130,533 105,862 Total current lease liabilities $ 161,516 $ 109,644 Non-current portion of operating lease liabilities Other non-current liabilities $ 39,116 $ 10,122 Non-current portion of finance lease liabilities Non-current finance lease liabilities — 40,083 Total non-current lease liabilities $ 39,116 $ 50,205 Weighted-average remaining lease term (years): Operating leases 5.0 4.5 Finance leases 3.7 4.7 Weighted-average discount rate: Operating leases 6.0% 13.8% Finance leases 5.2% 6.4% Lease expense for the operating and short-term leases for the years ended December 31, 2021 and 2020 was as follows (in thousands): Year Ended December 31, 2021 2020 Operating lease expense $ 37,027 $ 2,462 Short-term lease expense 468,210 66,805 Variable lease expense 116,435 4,854 Finance lease expense: ROU assets expensed $ 112,528 $ 242,009 Interest expense 7,241 3,097 Total finance lease expense $ 119,769 $ 245,106 Supplemental cash flow information related to leases for the year ended December 31, 2021 and 2020 was as follows (in thousands): Year Ended December 31, 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used in operating leases $ 203,991 $ 63,634 Operating cash flows used in finance leases 7,241 3,097 Financing cash flows used in finance leases 127,907 96,065 ROU assets obtained in exchange for operating lease obligations $ 66,682 $ 5,590 ROU assets obtained in exchange for finance lease obligations 112,528 242,009 As of December 31, 2021, maturities of lease liabilities were as follows (in thousands): Year Amount 2022 $ 166,244 2023 7,104 2024 7,238 2025 7,361 2026 7,344 Thereafter 19,186 Total minimum lease payments 214,477 Less: imputed interest (13,845) Total lease liabilities $ 200,632

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Convertible Notes In 2016, the Company issued $325 million aggregate principal amount of convertible senior unsecured notes that will mature on February 1, 2023 (the “Notes”). The Notes are senior unsecured debt obligations and were issued at par. The Notes were issued pursuant to an indenture dated January 29, 2016 (the “Indenture”) between the Company and the trustee. The Company received $315.0 million in net proceeds from the offering after deducting underwriting fees and offering expenses. The Notes bear cash interest at a rate of 3.75%, payable on February 1 and August 1 of each year, beginning on August 1, 2016. The Notes are not redeemable prior to maturity and are convertible into shares of the Company’s common stock. As a result of the Company’s one-for-twenty reverse stock split in 2019 and pursuant to Section 14.04(a) of the Indenture, the Notes are initially convertible into approximately 2,385,800 shares of the Company’s common stock based on the initial conversion rate of 7.3411 shares of the Company’s common stock per $1,000 principal amount of the Notes. This represents an initial conversion price of approximately $136.20 per share of the Company’s common stock, representing an approximate 22.5% conversion premium based on the last reported sale price of the Company’s common stock of $111.20 per share on January 25, 2016. In addition, the holders of the Notes may require the Company to repurchase the Notes at par value plus accrued and unpaid interest following the occurrence of a Fundamental Change (as described in the Indenture). If a holder of the Notes converts upon a Make-Whole Adjustment Event (as described in the Indenture), they may be eligible to receive a make-whole premium through an increase to the conversion rate up to a maximum of 8.9928 shares per $1,000 principal amount of Notes (subject to other adjustments as described in the Indenture). The Notes are accounted for in accordance with ASC 470-20, Debt with Conversion and Other Options (“ASC 470-20”) and ASC 815-40, Contracts in Entity’s Own Equity (“ASC 815-40”). Under ASC 815-40, to qualify for equity classification (or non-bifurcation, if embedded) the instrument (or embedded feature) must be both (1) indexed to the issuer’s stock and (2) meet the requirements of the equity classification guidance. Based upon the Company’s analysis, it was determined the Notes do contain embedded features indexed to its own stock, but do not meet the requirements for bifurcation, and therefore do not need to be separately accounted for as an equity component. Since the embedded conversion feature meets the equity scope exception from derivative accounting, and also since the embedded conversion option does not need to be separately accounted for as an equity component under ASC 470-20, the proceeds received from the issuance of the convertible debt were recorded as a liability on the consolidated balance sheets. In connection with the issuance of the Notes, the Company also paid $38.5 million, including expenses, to enter into privately negotiated capped call transactions with certain financial institutions (the “capped call transactions”). The capped call transactions are generally expected to reduce the potential dilution upon conversion of the Notes in the event that the market price per share of the Company’s common stock, as measured under the terms of the capped call transactions, is greater than the strike price of the capped call transactions, which initially corresponds to the conversion price of the Notes, and is subject to anti-dilution adjustments generally similar to those applicable to the conversion rate of the Notes. The cap price of the capped call transactions will initially be $194.60 per share, which represented a premium of approximately 75% based on the last reported sale price of the Company’s common stock of $111.20 per share on January 25, 2016, and is subject to certain adjustments under the terms of the capped call transactions. If, however, the market price per share of the Company’s common stock, as measured under the terms of the capped call transactions, exceeds the cap price, there would nevertheless be dilution upon conversion of the Notes to the extent that such market price exceeds the cap price. The Company evaluated the capped call transactions under ASC 815-10, Derivatives and Hedging – Overall and determined that it should be accounted for as a separate transaction and that the capped call transactions will be classified as an equity instrument. The Company incurred approximately $10.0 million of debt issuance costs in 2016 relating to the issuance of the Notes, which were recorded as a reduction to the Notes on the consolidated balance sheet. The $10.0 million of debt issuance costs is being amortized and recognized as additional interest expense over the seven-year contractual term of the Notes on a straight-line basis, which approximates the effective interest rate method. The Company also incurred $0.9 million of expenses related to the capped call transactions, which were recorded as a reduction to additional paid-in-capital. Total convertible notes payable consisted of the following at (in thousands): December 31, 2021 2020 Principal amount of Notes $ 325,000 $ 325,000 Unamortized debt issuance costs (1,542) (2,965) Total convertible notes payable $ 323,458 $ 322,035 Interest expense incurred in connection with the Notes consisted of the following (in thousands): Year Ended December 31, 2021 2020 2019 Coupon interest at 3.75% $ 12,188 $ 12,188 $ 12,188 Amortization of debt issuance costs 1,424 1,424 1,424 Total interest expense on Notes $ 13,612 $ 13,612 $ 13,612

Preferred Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Preferred Stock	Preferred StockIn June 2020, the Company entered into a redeemable Series A Convertible Preferred Stock Subscription Agreement, pursuant to which the Company agreed to issue and sell in a private placement 438,885 shares of its newly designated redeemable Series A Convertible Preferred Stock, par value $0.01 per share (“Preferred Stock”), at a purchase price of $455.70 per share, for total gross proceeds of $200.0 million. During the fourth quarter of 2020, all outstanding shares of Preferred Stock were converted and the Company issued 4,388,850 shares of common stock, par value $0.01 per share, and reclassified $199.8 million from Preferred stock to additional paid in capital. The Company recognized a beneficial conversion feature of approximately $24.1 million at the time of issuance of the Preferred Stock that was recorded in additional paid-in capital and accumulated deficit as the Preferred Stock issuance was contingently redeemable and convertible at any time at the option of the holder.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity In June 2021, the Company entered into an At Market Issuance Sales Agreement (the "June 2021 Sales Agreement"), which allows it to issue and sell up to $500 million in gross proceeds of shares of its common stock, and terminated its existing At Market Issuance Sales agreement. As of December 31, 2021, no shares had been sold under the June 2021 Sales Agreement. During 2021 and 2020, the Company sold 2.6 million and 32.4 million, respectively, of shares of its common stock resulting in net proceeds of approximately $565 million and $877 million, respectively, under its various At Market Issuance Sales Agreement.

Other Financial Information

Other Financial Information	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other Financial Information	Other Financial Information Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following at December 31 (in thousands): December 31, 2021 2020 Prepaid expenses $ 120,029 $ 171,602 Other current assets 53,491 9,662 Prepaid expenses and other current assets $ 173,520 $ 181,264 Property and Equipment, net Property and equipment is comprised of the following at December 31 (in thousands): December 31, 2021 2020 Land and buildings $ 83,534 $ 79,096 Machinery and equipment 119,998 31,609 Leasehold improvements 10,282 9,684 Computer hardware 9,670 6,126 Construction in progress 35,114 71,232 258,598 197,747 Less: accumulated depreciation (29,902) (17,793) Property and equipment, net $ 228,696 $ 179,954 Approximately $168.0 million of net assets used in operations were located in the Czech Republic. Depreciation expense was approximately $12.5 million, $4.3 million, and $5.1 million for the years ended December 31, 2021, 2020, and 2019, respectively. Accrued Expenses Accrued expenses consist of the following at December 31 (in thousands): December 31, 2021 2020 Employee benefits and compensation $ 38,419 $ 20,752 Research and development accruals 577,100 99,994 Other accrued expenses 58,212 16,644 Accrued expenses $ 673,731 $ 137,390

Revenue

Revenue	12 Months Ended
	Dec. 31, 2021
Grants, U.S. Government Contract and Joint Venture [Abstract]
Revenue	Revenue The Company recognizes revenue from the performance of research and development activities under government contracts and grant, license, and clinical development agreements, and from royalties under its collaboration and license agreements that include the sale of Matrix-M TM adjuvant. The Company's accounts receivable included $419.7 million and $262.0 million related to amounts that were billed to customers as of December 31, 2021 and December 31, 2020, respectively. Accounts receivable also included $35.3 million related to amounts which had not yet been billed to customers as of December 31, 2021. There were no amounts which had not yet been billed to customers as of December 31, 2020. During the year ended December 31, 2021, changes in the Company's accounts receivables and deferred revenue balances were as follows (in thousands): December 31, 2020 Additions Deductions December 31, 2021 Contract receivables: Accounts receivable $ 262,012 2,432,268 (2,239,287) $ 454,993 Contract liabilities Deferred revenue (1) $ 273,228 1,598,152 (275,908) $ 1,595,472 (1) Amount is comprised of $1.4 billion of current Deferred revenue and $172.5 million of non-current Deferred revenue. The aggregate amount of the transaction price allocated to performance obligations that were unsatisfied (or partially unsatisfied), excluding amounts related to sales-based royalties, was approximately $8 billion as of December 31, 2021. The timing to fulfill performance obligations related to grant agreements will depend on the results of the Company's research and development activities, including clinical trials. The timing to fulfill performance obligations related to advance purchase agreements (“APAs”) will depend on timing of product manufacturing, delivery, and receipt of marketing authorizations. The remaining unfilled performance obligations are expected to be fulfilled in less than one year. As of December 31, 2021, deferred revenue of $1.6 billion primarily related to upfront payments under APAs. The upfront payments are intended to assist the Company in funding investments related to building out and operating its manufacturing and distribution network, among other expenses, in support of its global supply commitment. Such upfront payments generally become non-refundable upon our achievement of certain development and commercial milestones. However, certain of the APAs may be terminated by the counterparty if the Company does not timely achieve requisite regulatory approval for NVX-CoV2373 in the relevant jurisdictions under such agreements. If the APAs were terminated, the refundable portion of the upfront payments would be repaid. Grants The Company recognized grant revenue as follows (in thousands): Year Ended December 31, 2021 2020 U.S. government partnership (a) $ 788,953 $ 204,727 U.S. DoD 21,683 12,519 CEPI 135,445 223,158 BMGF 2,628 12,806 Total grant revenue $ 948,709 $ 453,210 (a) U.S. government partnership formerly known as OWS U.S. Government Partnership In July 2020, the Company entered into a Project Agreement (the “Project Agreement”) with Advanced Technology International, Inc. (“ATI”), the Consortium Management Firm acting on behalf of the Medical CBRN Defense Consortium in connection with OWS. OWS is a partnership among components of the U.S. Department of Health and Human Services and the U.S. Department of Defense working to accelerate the development, manufacturing, and distribution of COVID-19 vaccines, therapeutics, and diagnostics. The Project Agreement relates to the Base Agreement the Company entered into with ATI in June 2020 (the “Base Agreement,” together with the Project Agreement, the “OWS Agreement”). The OWS Agreement requires the Company to conduct certain clinical, regulatory, and other activities, including a pivotal Phase 3 clinical trial to determine the safety and efficacy of NVX-CoV2373, and to manufacture and deliver to the U.S. government 100 million doses of the vaccine candidate. Funding under the OWS Agreement is payable to the Company for various development, clinical trial, manufacturing, regulatory, and other activities. The OWS Agreement contains terms and conditions that are customary for U.S. government agreements of this nature, including provisions giving the U.S. government the right to terminate the Base Agreement and/or the Project Agreement based on a reasonable determination that the funded project will not produce beneficial results commensurate with the expenditure of resources and that termination would be in the U.S. government’s interest. If the Project Agreement is terminated prior to completion, the Company is entitled to be paid for work performed and costs or obligations incurred prior to termination and consistent with the terms of the OWS Agreement. In July 2021, the U.S. government instructed the Company to prioritize alignment with the U.S. Food and Drug Administration (“FDA”) on the Company's analytic methods before conducting additional U.S. manufacturing and further indicated that the U.S. government will not fund additional U.S. manufacturing until such agreement has been made. In the third quarter of 2021, the Company updated its estimate-at-completion to reflect the impact of the change to the recognition of the fixed fee under the contract. The U.S. government also instructed the Company to proceed with work under the OWS Agreement related to all other activities, including ongoing clinical trials and nonclinical studies, regulatory interactions, analytics/assays and characterization of manufactured vaccine, and project management. In October 2021 and January 2022, the U.S. government extended the prescribed time to meet its July 2021 instructions until April 2022. The performance period under the Project Agreement extends through 2023 to cover clinical trial activities, subject to early termination by the U.S. government or extension by mutual agreement of the parties. Under the OWS Agreement, the Company was originally entitled to receive funding of up to $1.75 billion to support certain activities related to the development of NVX-CoV2373 and the manufacture and delivery of the vaccine candidate to the U.S. government. Pursuant to the OWS Agreement, the Company is authorized to make expenditures or incur obligations of up to $1.75 billion. In August 2021, the Company's OWS agreement was amended to increase the contract ceiling by $52.9 million for a revised total of $1.8 billion. The agreement’s authorized funding remains unchanged at $1.75 billion for support of certain activities related to the development of NVX-CoV2373 and the manufacture and delivery of 100 million doses of the vaccine candidate to the U.S. government. As of December 31, 2021, the Company had recognized $1.0 billion in revenue related to the OWS Agreement since the inception of the contract, leaving $0.8 billion remaining to spend. The Company and the U.S. government will determine the timing and amounts for delivery of NVX-CoV2373 doses upon U.S authorization and the Company intends to pursue additional U.S. procurement agreements for supply of NVX-CoV2373 doses. U.S. Department of Defense In June 2020, the Company entered into a letter contract that was later amended in January 2021 (the “DoD Contract”) with the DoD Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (“JPEO-CRBND-EB”), under which JPEO-CRBND-EB agreed to provide funding of up to $45.7 million to the Company to support the manufacture of NVX-CoV2373. Under the DoD Contract, the Company is authorized to make expenditures or incur obligations up to the full amount of the funding. Under the DoD Contract, the Company is expected to deliver 10 million doses of NVX-CoV2373 to the DoD. The 10 million doses of NVX-CoV2373 may be used in Phase 2/3 clinical trials or under an EUA, if approved by the FDA. Pursuant to the DoD Contract, if NVX-CoV2373 is approved by the FDA, the DoD is entitled to most-favored customer status for a period of five years from the award of the DoD Contract, meaning that the Company cannot give any comparable commercial client in the United States more favorable pricing than the DoD under similar transactional circumstances. Coalition for Epidemic Preparedness Innovations In May 2020, the Company entered into a restated funding agreement which was amended in November 2020 (the “CEPI Funding Agreement”) with CEPI, under which CEPI agreed to provide funding of up to $399.5 million to the Company to support the development of NVX-CoV2373. The CEPI Funding Agreement provides up to $257.0 million in Grant Funding and up to $142.5 million in Forgivable Loan Funding, which are loans in the form of one or more forgivable no-interest term loans in order to prepay certain manufacturing activities and are not subject to restrictive or financial covenants. Payments received under the CEPI Forgivable Loan Funding are only repayable if the proceeds of sales to one or more third parties of NVX-CoV2373 cover the Company’s costs of manufacturing such vaccine candidate, not including manufacturing costs funded by CEPI. The Company anticipates making repayments starting in 2022. Under the terms of the CEPI Funding Agreement, among other things, the Company and CEPI agreed on the importance of global equitable access to any vaccines produced pursuant to the CEPI Funding Agreement. Any such vaccines, if approved, are expected to be procured and allocated through global mechanisms under discussion as part of the Access to COVID-19 Tools (ACT) Accelerator, an international initiative launched by the World Health Organization (“WHO”), Gavi the Vaccine Alliance, CEPI, and other global non-governmental organizations and governmental leaders in 2020. The scope and continuation of the CEPI Funding Agreement may be amended depending on ongoing developments of the COVID-19 outbreak and the success of NVX-CoV2373 relative to other third-party COVID-19 vaccine candidates or treatments. If the WHO, CEPI, or a regulatory authority having jurisdiction over a clinical trial of NVX-CoV2373 determines that a third-party product candidate has substantially greater potential than a Company vaccine product, the Company must cease its clinical trial in the relevant region, and will be reimbursed for any costs incurred as a result thereof. In addition, CEPI has the right to unilaterally terminate the CEPI Funding Agreement if CEPI reasonably determines that (i) there are material safety, regulatory, or ethical issues with the development of NVX-CoV2373, (ii) NVX-CoV2373 development should be limited in scope or terminated, (iii) the Company becomes unable to discharge its obligations under the agreement, (iv) the Company fails to meet certain milestones, or (v) the Company commits fraud or a financial irregularity. Payments received in advance that are related to future performance are deferred and recognized as revenue when the research and development activities are performed. Cash payments received under the CEPI Funding Agreement are restricted as to their use until expenditures contemplated in the funding agreements are incurred. Bill & Melinda Gates Foundation In support of the Company's development of ResVax, the project name for the respiratory syncytial virus (“RSV”) vaccine candidate, in September 2015, the Company entered into the grant agreement with BMGF (the “BMGF Grant Agreement”), under which it was awarded a grant totaling up to $89.1 million (the “Grant”). The Grant supported ResVax development activities, including the Company's global Phase 3 clinical trial in pregnant women in their third trimester and other regulatory efforts. The BMGF Grant Agreement was completed as of December 31, 2021. The Company concurrently entered into a Global Access Commitments Agreement (“GACA”) with BMGF as a part of the BMGF Grant Agreement. Under the terms of the GACA, among other things, the Company agreed to make a certain amount of ResVax available and accessible at affordable pricing to people in certain low- and middle-income countries. Unless terminated earlier by BMGF, the GACA will continue in effect until the later of 15 years from its effective date, or 10 years after the first sale of a product under defined circumstances. The term of the GACA may be extended in certain circumstances, by a period of up to five In July 2020, the Company entered into a grant agreement with BMGF (the “BMGF SA Grant Agreement”) under which it was awarded and received a grant of $15.0 million to support a Phase 2b clinical trial in the Republic of South Africa to evaluate the safety, immunogenicity, and potential efficacy of NVX-CoV2373. As of December 31, 2021, the Company had recognized the full amount of the grant as revenue. Payments received in advance that are related to future performance are deferred and recognized as revenue when the research and development activities are performed. Cash payments received under the BMGF Grant Agreement and the BMGF SA Grant Agreement are restricted as to their use until expenditures contemplated in the agreements are incurred. Royalties and Other For the year ended December 31, 2021, the Company recognized $178.6 million in revenue related to sales-based royalties. For the year ended December 31, 2020, the Company recognized $20.0 million related to a development and commercial milestone payment. Serum Institute of India Private Limited In July 2020, the Company entered into a supply and license agreement with Serum Institute of India Private Limited (“SIIPL”), which was amended in September 2020 and amended and restated in July 2021, under which the Company granted exclusive and non-exclusive licenses to SIIPL for the development, co-formulation, filling and finishing, registration, and commercialization by SIIPL of NVX-CoV2373. SIIPL agreed to purchase Matrix-M™ adjuvant from the Company and the Company granted SIIPL a non-exclusive license to manufacture the antigen drug substance component of NVX-CoV2373 in SIIPL’s licensed territory solely for use in the manufacture of NVX-CoV2373 under the terms of the agreement. The parties will equally split the revenue from sale of NVX-CoV2373 by SIIPL in its licensed territory, net of agreed costs. The Company granted to SIIPL (i) an exclusive license in India during the agreement and (ii) a non-exclusive license (a) during the “Pandemic Period” (as declared by the WHO) in all countries other than specified countries designated by the World Bank as upper-middle or high-income countries, with respect to which the Company retains rights, and (b) after the Pandemic Period, in only those countries designated as low or middle-income by the World Bank. Following the Pandemic Period, the Company may notify SIIPL of any bona fide opportunities for the Company to license NVX-CoV2373 to a third party in such low and middle- income countries and SIIPL would have an opportunity to match or improve such third-party terms, failing which, the Company would have the discretion to remove one or more non-exclusive countries from SIIPL’s license. In October 2021, the Company entered into a supply agreement and a contract development manufacturing agreement with SIIPL and Serum Life Sciences Limited ("SLS") under which SIIPL and SLS will supply the Company with NVX-CoV2373 for commercialization in certain territories. Takeda Pharmaceutical Company Limited In February 2021, the Company finalized a collaboration and license agreement with Takeda Pharmaceutical Company Limited (“Takeda”), under which the Company granted Takeda an exclusive license to develop, manufacture, and commercialize NVX-CoV2373 in Japan. Under the agreement, Takeda purchases Matrix-M™ adjuvant from the Company to manufacture doses of NVX-CoV2373 and the Company is entitled to receive payments from Takeda based on the achievement of certain development and commercial milestones, as well as a portion of net profits from the sale of NVX-CoV2373. In September 2021, Takeda finalized an agreement with the Government of Japan’s Ministry of Health, Labour and Welfare ("MHLW") for the purchase of 150 million doses of NVX-CoV2373. The announcement followed an update from MHLW on its ongoing efforts to secure coronavirus vaccine for the citizens of Japan. These efforts include vaccine procurement by Takeda pursuant to the terms of the collaboration and license agreement that the Company entered into with Takeda in February 2021. In 2020, the Company recognized revenue as a result of achieving a development milestone from the Takeda arrangement in the amount of $20.0 million, which is included in Royalties and other revenue on the Statements of Operations. The Company is eligible for a future milestone payment of an additional $20.0 million upon regulatory approval in Japan. SK bioscience, Co., Ltd. In February 2021, the Company finalized an expanded collaboration and license agreement with SK bioscience, Co., Ltd. ("SK bioscience") to manufacture and commercialize NVX-CoV2373 for sale to the government of Korea. Concurrently, SK bioscience finalized an APA with the Korean government to supply 40 million doses of NVX-CoV2373 to the Republic of Korea beginning in 2021. The agreement is in addition to the Company's existing manufacturing arrangement with SK bioscience entered into in August 2020. Under the collaboration agreement, SK bioscience was granted an exclusive license to develop, manufacture, and commercialize NVX-CoV2373 in the Republic of Korea. SK bioscience will pay the Company a tiered royalty in the low to middle double-digit range on the sale of NVX-CoV2373. In May 2021, the Company entered a non-binding Memorandum of Understanding with the Ministry of Health and Welfare of Korea and SK bioscience to explore further cooperation in the development and manufacturing of vaccines, including NVX-CoV2373, and to potentially explore the development of new vaccine products with SK bioscience, including COVID-19 variant vaccines and/or an influenza/COVID-19 combination vaccine. SK bioscience expanded its capacity to manufacture the antigen component of NVX-CoV2373 and, in December 2021, the Company amended the collaboration and license agreement to grant a non-exclusive license to cover Thailand and Vietnam, subject to a low to middle double-digit royalty, and for SK biosciences to supply the antigen component of NVX-CoV2373 to the Company for use in the final drug product globally, including product distributed by the COVAX Facility. Advance Purchase Agreements (APAs) During the years ended December 31, 2021 and 2020, the Company entered into various APAs for NVX-CoV2373. Under the terms of the Company's advance purchase agreements, government counterparties make upfront payments and have certain termination rights, or rights to reduce or cancel orders, if regulatory approval for the vaccine is not received or if supply is materially interrupted, delayed, or deferred. The Company records such upfront payments as deferred revenue and will recognize revenue when the vaccine is delivered to its customers. As of December 31, 2021 and 2020, the Company had deferred revenue related to APAs of $1.6 billion and $45.0 million, respectively. Under the terms of the APA with Gavi and a separate purchase agreement between Gavi and SIIPL, 1.1 billion doses of NVX-CoV2373 are to be made available to countries participating in the COVAX Facility. The Company expects to manufacture and distribute 350 million doses of NVX-CoV2373 to countries participating under the COVAX Facility. Under a separate purchase agreement with Gavi, SIIPL is expected to manufacture and deliver the balance of the 1.1 billion doses of NVX-CoV2373 for low- and middle-income countries participating in the COVAX Facility. The Company expects to deliver doses with antigen and adjuvant manufactured at facilities directly funded under the Company's funding agreement with CEPI, with initial doses supplied by SIIPL and SLS under a supply agreement. The Company expects to supply significant doses that Gavi would allocate to low-, middle- and high-income countries, subject to certain limitations, utilizing a tiered pricing schedule and Gavi may prioritize such doses to low- and middle- income countries, at lower prices. Additionally, the Company may provide additional doses of NVX-CoV2373, to the extent available from CEPI funded manufacturing facilities, in the event that SIIPL cannot materially deliver expected vaccine doses to the COVAX Facility. Under the agreement, the Company received an upfront payment from Gavi of $350.0 million in 2021 and has recorded a receivable as of December 31, 2021, for an additional $350.0 million because the Company secured EUL for NVX-CoV2373 by the WHO in December 2021, which are recorded as deferred revenue. The Company also has an APA with the European Commission acting on behalf of various European Union member states to supply a minimum of 20 million and up to 100 million initial doses of NVX-CoV2373, with the option for the Commission to purchase an additional 100 million doses up to a maximum aggregate of 200 million doses in one or more tranches, through 2023. Under the terms of the APA, the Company agreed to manufacture the vaccine in facilities located in the European Union and ensure continued efficacy of the vaccine against variants of the SARS-CoV-2 virus. Pursuant to the terms of the APA, the Company is prohibited from supplying NVX-CoV2373 to any third party if such delivery would impede or limit the fulfillment of the Company’s obligations to the European Commission under the APA, except with respect to the Company’s obligations under its APA with Gavi.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Equity Plans The 2015 Stock Incentive Plan, as amended (“2015 Plan”), was approved at the Company’s annual meeting of stockholders in June 2015. Under the 2015 Plan, equity awards may be granted to officers, directors, employees, and consultants of and advisors to the Company and any present or future subsidiary. The 2015 Plan authorizes the issuance of up to 12.4 million shares of common stock under equity awards granted under the 2015 Plan, which includes an increase of 1.5 million shares approved for issuance under the 2015 Plan at the Company’s 2021 annual meeting of stockholders. All such shares authorized for issuance under the 2015 Plan have been reserved. The 2015 Plan will expire on March 4, 2025. The Amended and Restated 2005 Stock Incentive Plan (“2005 Plan”) expired in February 2015 and no new awards may be made under such plan, although awards will continue to be outstanding in accordance with their terms. The 2015 Plan permits and the 2005 Plan permitted the grant of stock options (including incentive stock options), restricted stock, stock appreciation rights, and restricted stock units. In addition, under the 2015 Plan, unrestricted stock, stock units, and performance awards may be granted. Stock options and stock appreciation rights generally have a maximum term of 10 years and may be or were granted with an exercise price that is no less than 100% of the fair market value of the Company’s common stock at the time of grant. Grants of stock options are generally subject to vesting over periods ranging from one The Company recorded stock-based compensation expense in the consolidated statements of operations as follows (in thousands): Year Ended December 31, 2021 2020 2019 Research and development $ 86,928 $ 55,955 $ 8,436 General and administrative 96,698 72,080 8,612 Total stock-based compensation expense $ 183,626 $ 128,035 $ 17,048 As of December 31, 2021, there was approximately $190 million of total unrecognized compensation expense related to unvested stock options, stock appreciation rights, restricted stock units and the Employee Stock Purchase Plan, as amended (the “ESPP”). This unrecognized non-cash compensation expense is expected to be recognized over a weighted-average period of 1.2 years and will be allocated between research and development and general and administrative expenses accordingly. This estimate does not include the impact of other possible stock-based awards that may be made during future periods and awards that require approval by the stockholders. The aggregate intrinsic value represents the total intrinsic value (the difference between the Company’s closing stock price on the last trading day of the period and the exercise price, multiplied by the number of in-the-money stock options and stock appreciation rights) that would have been received by the holders had all stock option and stock appreciation rights holders exercised their stock options and stock appreciation rights on December 31, 2021. This amount is subject to change based on changes to the closing price of the Company’s common stock. The aggregate intrinsic value of stock options and stock appreciation rights exercises and vesting of restricted stock units for 2021, 2020, and 2019 was $453.8 million, $187.3 million, and $0.5 million, respectively. Stock Options and Stock Appreciation Rights The following is a summary of stock options and stock appreciation rights activity under the 2015 Plan and the 2005 Plan for the year ended December 31, 2021: 2015 Plan 2005 Plan Stock Options Weighted- Stock Weighted- Outstanding at January 1, 2021 5,420,463 $ 38.05 214,186 $ 88.11 Granted 81,959 $ 177.84 — $ — Exercised (1,778,688) $ 31.11 (145,961) $ 78.11 Canceled (87,897) $ 120.62 — $ — Outstanding at December 31, 2021 3,635,837 $ 42.60 68,225 $ 109.52 Shares exercisable at December 31, 2021 1,170,259 $ 57.01 68,225 $ 109.52 Shares available for grant at December 31, 2021 3,716,636 The fair value of stock options granted under the 2015 Plan was estimated at the date of grant or the date upon which the 2015 Plan was approved by the Company’s stockholders for certain stock options granted in 2020 and 2019 using the Black-Scholes option-pricing model with the following assumptions: Year Ended December 31, 2021 2020 2019 Weighted average Black-Scholes fair value of stock $158.02 $80.48 $4.98 Risk-free interest rate 0.5%-1.3% 0.2%-1.5% 1.5%-2.6% Dividend yield —% —% —% Volatility 124.7%-142.0% 116.0%-152.2% 105.4%-134.1% Expected term (in years) 4.1-6.1 3.9-7.6 3.9-7.5 The total aggregate intrinsic value and weighted-average remaining contractual term of stock options and stock appreciation rights outstanding under the 2015 Plan and 2005 Plan as of December 31, 2021 was approximately $376 million and 7.7 years, respectively. The total aggregate intrinsic value and weighted-average remaining contractual term of stock options and stock appreciation rights exercisable under the 2015 Plan and 2005 Plan as of December 31, 2020 was approximately $108 million and 6.8 years, respectively. Restricted Stock Units The following is a summary of restricted stock units activity for the year ended December 31, 2021: Number of Per Share Outstanding and unvested at January 1, 2021 1,044,980 $ 72.59 Restricted stock units granted 316,571 $ 191.82 Restricted stock units vested (488,370) $ 69.02 Restricted stock units forfeited (53,353) $ 141.01 Outstanding and unvested at December 31, 2021 819,828 $ 116.70 Employee Stock Purchase Plan The ESPP was approved at the Company’s annual meeting of stockholders in June 2013. The ESPP currently authorizes an aggregate of 600,000 shares of common stock to be purchased. The ESPP allows employees to purchase shares of common stock of the Company at each purchase date through payroll deductions of up to a maximum of 15% of their compensation, at 85% of the lesser of the market price of the shares at the time of purchase or the market price on the beginning date of an option period (or, if later, the date during the option period when the employee was first eligible to participate). At December 31, 2021, there were 164,495 shares available for issuance under the ESPP. The ESPP is considered compensatory for financial reporting purposes. As such, the fair value of ESPP shares was estimated at the date of grant using the Black-Scholes option-pricing model with the following assumptions: Year Ended December 31, 2021 2020 2019 Range of Black-Scholes fair values of ESPP $83.47-$238.85 $2.57-$92.67 $2.57-$35.00 Risk-free interest rate 0.1%-0.2% 0.2%-2.6% 1.2%-2.6% Dividend yield —% —% —% Volatility 114.9%-159.4% 66.6%-189.7% 52.2%-171.6% Expected term (in years) 0.5-2.0 0.5-2.0 0.5-2.0

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2021
Payment for Pension and Other Postretirement Benefits [Abstract]
Employee Benefits	Employee Benefits The Company maintains a defined contribution 401(k) retirement plan, pursuant to which employees may elect to contribute up to 100% of their compensation on a tax deferred basis up to the maximum amount permitted by the Internal Revenue Code of 1986, as amended. The Company matches 100% of the first 3% of the participants’ deferral, and 50% on the next 2% of the participants’ deferral, up to a potential 4% Company match. The Company’s matching contributions to the 401(k) plan vest immediately. Under its 401(k) plan, the Company has recorded expense of $3.4 million, $0.9 million, and $1.0 million in 2021, 2020, and 2019, respectively. The Company’s foreign subsidiaries have pension plans under local tax and labor laws and are obligated to make contributions to the plan. Contributions and other expenses related to this plan were $1.7 million, $1.0 million, and $0.7 million in 2021, 2020, and 2019, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s income (loss) from operations before income tax expense by jurisdiction for the years ended December 31 are as follows (in thousands): Year Ended December 31, 2021 2020 2019 Domestic $ (1,633,016) $ (455,253) $ (124,189) Foreign (81,520) 36,994 (8,505) Loss before income tax expense $ (1,714,536) $ (418,259) $ (132,694) During the year ended December 31, 2021, the Company recognized $29.2 million of income tax expense related to foreign withholding tax on royalties. During the years ended December 31, 2020 and 2019, the Company recognized no income tax expense. A reconciliation of the provision for income tax to the amount computed by applying the U.S. federal statutory tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2021 2020 2019 Statutory federal tax rate (21) % (21) % (21) % State income taxes, net of federal benefit (6) % (3) % (2) % Research and development and other tax credits (1) % — % (3) % Non-deductible expenses 2 % 4 % — % Non-cash stock-based compensation (4) % (7) % — % Foreign tax expense 1 % — % — % Other 1 % 1 % 1 % Change in tax rate — % (5) % 3 % Change in valuation allowance 30 % 31 % 22 % Income tax provision 2 % — % — % As of December 31, 2021, the Company has available federal, state, and foreign net operating losses of $3.2 billion, $2.8 billion, and $127.6 million, respectively, that may be applied against future taxable income. Federal net operating losses of $0.9 billion will expire in the years 2022 to 2037. The remaining $2.3 billion of federal net operating losses can be carried forward indefinitely. A portion of the foreign net operating losses will begin to expire in 2023. The Company also has research tax credits of $44.6 million that continue to expire in 2022. Utilization of the net operating loss carryforwards and credits may be subject to an annual limitation due to ownership changes of the Company. As of December 31, 2021, the Company does not expect such limitation, if any, to impact the use of the net operating losses and business tax credits. The Company files income tax returns in the U.S. federal jurisdiction and in various states, as well as in Sweden and the Czech Republic. The Company has U.S. tax net operating losses and credit carryforwards that are subject to examination from 2002 through 2021. The returns in Sweden are subject to examination from 2015 through 2021 and the returns for the Czech Republic are subject to examination from 2018 through 2021. The significant components of the Company’s deferred tax assets and liabilities as of December 31 were as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforward $ 845,731 $ 325,655 Foreign net operating loss carryforward 25,625 8,620 Research tax credits 44,618 35,065 Lease liability 52,852 39,548 Deferred revenue 20,262 60,657 Non-cash stock-based compensation 24,698 22,577 Original discount interest 1,729 3,177 Other 11,801 12,019 Total deferred tax assets 1,027,316 507,318 Valuation allowance (1,015,333) (504,788) Net deferred tax assets $ 11,983 $ 2,530 Deferred tax liabilities: ROU assets (10,071) (1,253) Intangibles (1,034) (1,198) Other (878) (79) Total deferred tax liabilities $ (11,983) $ (2,530) Net deferred tax assets $ — $ — The Company has evaluated the positive and negative evidence bearing upon the realization of its deferred tax assets, including its history of significant losses in every year since inception and, in accordance with U.S GAAP, has fully reserved the net deferred tax asset. The Company concluded that realization of its net deferred tax assets is not more-likely-than-not to be realized as of December 31, 2021. The valuation allowance increased by $510.5 million and $139.0 million for the years ended December 31, 2021 and 2020, respectively, primarily due to the increase in net operating loss carry-forwards and research and development tax credits. On a periodic basis, the Company reassesses the valuation allowance on its deferred income tax assets, weighing positive and negative evidence to assess the recoverability of the deferred tax assets. In 2021, the Company reassessed the valuation allowance and considered negative evidence, including its cumulative losses over the three years ended December 31, 2021, and positive evidence, including its recent regulatory authorizations for NVX-CoV2373. After assessing both the negative and positive evidence, the Company concluded that it should maintain the valuation allowance on its net operating losses and its other deferred tax assets as of December 31, 2021. The release of the valuation allowance, as well as the exact timing and the amount of such release, continue to be subject to, among other things, the Company's level of profitability, revenue growth, clinical program progression, and expectations regarding future profitability. The Company's total deferred tax asset balance subject to the valuation allowance was $1.0 billion at December 31, 2021. The Company recognizes the effect of a tax position when it is more likely than not, based on the technical merits, that the tax position will be sustained upon examination. A reconciliation of the beginning and ending amounts of unrecognized tax benefits in the year ended December 31, 2021, 2020, and 2019 is as follows (in thousands): Year Ended December 31, 2021 2020 2019 Unrecognized tax benefits balance at January 1, $ 8,766 $ — $ — Additions for tax positions of current year 4,158 1,413 — Additions for tax positions of prior years — 7,353 — Reductions for tax positions of prior year (1,770) — — Settlements of tax positions of prior years — — — Unrecognized tax benefits balance at December 31, $ 11,154 $ 8,766 $ —

Related Party Transaction

Related Party Transaction	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transaction	Related Party TransactionIn June 2020, in advance of David M. Mott joining the Company’s Board of Directors, the Company agreed to sell 32,916 shares of common stock to him at a purchase price of $45.57 per share, reflecting the closing price of the Company’s common stock on the trading date prior to the date the parties’ agreement regarding the sale, for total gross proceeds of $1.5 million. Mr. Mott joined the Company’s Board of Directors later in the same month.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitment and Contingencies Legal Matters On February 26, 2021, a Novavax stockholder named Thomas Golubinski filed a derivative complaint against members of the Novavax board of directors and members of senior management in the Delaware Court of Chancery, captioned Thomas Golubinski v. Richard H. Douglas, et al. , No. 2021-0172-JRS. Novavax is deemed a nominal defendant. Golubinski challenged equity awards made in April 2020 and in June 2020 on the ground that they were “spring-loaded,” that is, made at a time when such board members or members of senior management allegedly possessed undisclosed positive material information concerning the Company. The complaint asserted claims for breach of fiduciary duty, waste, and unjust enrichment. The plaintiff sought an award of damages to the Company, an order rescinding both awards or requiring disgorgement, and an award of attorneys’ fees incurred in connection with the litigation. On May 10, 2021, the defendants moved to dismiss the complaint in its entirety. On June 17, 2021, the Company’s stockholders voted FOR ratification of the April 2020 awards and ratification of the June 2020 awards. Details of the ratification proposals are set forth in the Company’s Definitive Proxy Statement filed with the SEC on May 3, 2021. The results of the vote were disclosed in the Company’s Current Report on Form 8-K filed with the SEC on June 24, 2021. Thereafter, the plaintiff stipulated that, as a result of the outcome of the June 17, 2021 vote, the plaintiff no longer intends to pursue the lawsuit or any claim arising from the April 2020 and June 2020 awards. On August 23, 2021, the plaintiff filed a motion seeking an award of attorneys’ fees and expenses, to which the defendants filed an opposition. The action is currently stayed, and upon final resolution of the plaintiff’s motion for an award of fees and expenses, the action will be automatically dismissed. As such, the Company is not expecting any material estimable financial impact of the plaintiff's claim. On November 12, 2021, Sothinathan Sinnathurai filed a purported class action in the U.S. District Court for the District of Maryland against Novavax and certain members of senior management, captioned Sothinathan Sinnathurai v. Novavax, Inc., et al. , No. 8:21-cv-02910-TDC (the “Sinnathurai Action”). The complaint in the Sinnathurai Action alleges that the defendants made certain purportedly false and misleading statements concerning NVX-CoV2373, including with respect to the Company’s manufacturing capabilities and NVX-CoV2373’s regulatory and commercial prospects. The purported class is defined as those who purchased or otherwise acquired Novavax securities between March 2, 2021 and October 19, 2021. The complaint demands an award of damages on behalf of the purported class and attorneys’ fees incurred in connection with the litigation. On January 26, 2022, the court entered an order designating David Truong, Nuggehalli Balmukund Nandkumar, and Jeffrey Gabbert as co-lead plaintiffs in the Sinnathurai Action. The court has ordered the co-lead plaintiffs to file an amended complaint by March 11, 2022. The Company’s response to the amended complaint is due April 25, 2022. After the Sinnathurai Action was filed, three derivative lawsuits were filed and are currently pending in the U.S. District Court for the District of Maryland: Robert E. Meyer v. Stanley C. Erck, et al. , No. 8:21-cv-02996-TDC (the “Meyer Action”), Shui Shing Yung v. Stanley C. Erck, et al. , No. 8:21-cv-03248-TDC (the “Yung Action”), and William Kirst, et al. v. Stanley C. Erck, et al. , No. 8:22-cv-00024-TDC (the “Kirst Action”). The derivative lawsuits name members of the board of directors and certain members of senior management as defendants. Novavax is deemed a nominal defendant. The derivative plaintiffs assert derivative claims arising out of substantially the same alleged facts and circumstances as the Sinnathurai Action. Collectively, the derivative complaints assert claims for breach of fiduciary duty, insider selling, unjust enrichment, violation of federal securities law, abuse of control, waste, and mismanagement. Plaintiffs seek declaratory and injunctive relief, as well as an award of monetary damages and attorneys’ fees. Novavax removed the Kirst Action from the Circuit Court for Montgomery County, Maryland. On February 7, 2022, the plaintiffs in the Kirst Action filed a motion to remand the action to state court and, in response, the Company has filed an opposition. The Court also entered an order tolling the defendants’ time to respond to the complaints in the Meyer and Yung Actions pending submission of a joint proposed briefing schedule on any anticipated motion practice in those cases by March 25, 2022. On February 4, 2022, the Court entered an order consolidating the Meyer and Yung Actions. The financial impact of the claims is not estimable. The Company is also involved in various legal proceedings arising in the normal course of business. Although the outcomes of these legal proceedings are inherently difficult to predict, management does not expect the resolution of these legal proceedings to have a material adverse effect on the Company's financial position, results of operations, or cash flows. Purchase Commitments The Company has entered into agreements in the normal course of business with CMOs and CDMOs supplying the Company with production capabilities, and with vendors for preclinical studies, clinical trials, and other goods or services. A number of these arrangements are within the scope of lease accounting (see Note 7). Certain agreements provide for termination rights subject to termination fees. Under such agreements, the Company is contractually obligated to make payments to vendors, mainly to reimburse them for their estimated unrecoverable expenses. The exact amount of such obligations are dependent on the timing of termination, and the terms of the relevant agreement, and cannot be reasonably estimated. As of December 31, 2021, most of these agreements were active ongoing arrangements and the Company expects to receive value from these arrangements in the future. The Company recognizes fees related to obligations for terminated contracts where such fees are reasonably estimable. The Company did not accrue obligations that were not reasonably estimable. As of December 31, 2021, the Company had no non-cancelable purchase commitments with a remaining term of more than one year as compared with approximately $117 million as of December 31, 2020.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In January 2022, the Company sold 0.4 million shares of its common stock resulting in net proceeds of $34.7 million under the June 2021 Sales Agreement, with a remaining balance of $464.9 million available thereafter. In January and February 2022, the Company received authorization for Nuvaxovid TM from the regulatory authorities in Canada, Singapore, New Zealand, Great Britain, Australia, and South Korea. In January 2022, the Company submitted a request to the FDA for EUA of NVX-CoV2373. In February 2022, the Company’s Project Agreement with ATI was modified to include a Phase 3 efficacy study with respect to 2019n-CoV-301 in adolescents with a booster component and accordingly, the performance period under the Project Agreement was extended to December 31, 2023.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of Novavax, Inc. and its wholly owned subsidiaries, including Novavax AB and Novavax CZ. All intercompany accounts and transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain amounts reported in prior periods have been reclassified to conform to current period financial statement presentation. These reclassifications have no material effect on previously reported financial position, cash flows, or results of operations. The Company combined amounts previously reported as Government contracts revenue of $217.2 million and Grants revenue of $236.0 million for the year ended December 31, 2020, and Government contracts revenue of $7.5 million and Grants revenue of $8.4 million for the year ended December 31, 2019 into a single financial statement line item, Grants, in the consolidated statements of operations. Other revenue of $22.4 million for the year ended December 31, 2020, and $2.7 million for the year ended December 31, 2019 was reclassified to Royalties and other.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ materially from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of highly liquid investments with maturities of three months or less from the date of purchase. Cash and cash equivalents consist of the following (in thousands): December 31, 2021 2020 Cash $ 96,372 $ 122,312 Money market funds  361,822 96,116 Government-backed securities 266,250 44,250 Treasury securities — 44,052 Corporate debt securities 790,672 246,668 Cash and cash equivalents $ 1,515,116 $ 553,398 Cash equivalents are recorded at cost, which approximate fair value due to their short-term nature.
Marketable Securities	Marketable Securities Marketable securities consist of debt securities with maturities greater than three months from the date of purchase that have historically included commercial paper, government-backed securities, treasury securities, corporate notes, and agency securities. Classification of marketable securities between current and non-current is dependent upon the maturity date at the balance sheet date taking into consideration the Company’s ability and intent to hold the investment to maturity. Interest and dividend income are recorded when earned and included in investment income in the consolidated statements of operations. Premiums and discounts, if any, on marketable securities are amortized or accreted to maturity and included in investment income in the consolidated statements of operations. The specific identification method is used in computing realized gains and losses on the sale of the Company’s securities. The Company classifies its marketable securities with readily determinable fair values as “available-for-sale.” Investments in securities that are classified as available-for-sale are measured at fair market value in the consolidated balance sheets, and unrealized gains and losses on marketable securities are reported as a separate component of stockholders’ equity (deficit) until realized. Marketable securities are evaluated periodically to determine whether a decline in value is “other-than-temporary.” The term “other-than-temporary” is not intended to indicate a permanent decline in value. Rather, it means that the prospects for a near term recovery of value are not necessarily favorable, or that there is a lack of evidence to support fair values equal to, or greater than, the carrying value of the security. Management reviews criteria, such as the magnitude and duration of the decline, as well as the Company’s ability to hold the securities, including whether the Company will be required to sell a security prior to recovery of its amortized cost basis, the investment issuer’s financial condition and business outlook to predict whether the loss in value is other-than-temporary. If a decline in value is determined to be other-than-temporary, the value of the security is reduced and the impairment is recorded as other income (expense) in the consolidated statements of operations.
Fair Value Measurements	Fair Value Measurements The Company applies Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures (“ASC 820”), for financial and non-financial assets and liabilities. ASC 820 discusses valuation techniques, such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). The statement utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The following is a brief description of those three levels: • Level 1: Observable inputs such as quoted prices (unadjusted) in active markets for identical assets or liabilities. • Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. • Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions.
Restricted Cash	Restricted Cash The Company’s current and non-current restricted cash includes payments received under the Coalition for Epidemic Preparedness Innovations (“CEPI”) funding agreements, payments received under the Bill & Melinda Gates Foundation (“BMGF”) grant agreements, and cash collateral accounts under letters of credit that serve as security deposits for certain facility leases. CEPI and BMGF funds become unrestricted as the Company incurs expenses for services performed under these agreements. As of December 31, 2021 and 2020, the restricted cash balances (both current and non-current) consisted primarily of $10.4 million and $92.4 million, respectively, of payments under the CEPI funding agreements.
Accounts Receivable	Accounts Receivable The Company recognizes amounts due from customers as accounts receivable when its right to payment is unconditional. The Company has evaluated outstanding receivables to assess collectability, with consideration given to economic conditions, the aging of receivables, and customer-specific risks. There was no allowance for doubtful accounts as of December 31, 2021, and 2020. There was no bad debt expense for the years ended December 31, 2021, 2020 or 2019.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments expose the Company to concentration of credit risk and consist primarily of cash and cash equivalents and marketable securities. The Company’s investment policy limits investments to certain types of instruments, including asset-backed securities, high-grade corporate debt securities, and money market funds, places restrictions on maturities and concentrations in certain industries and requires the Company to maintain a certain level of liquidity. At times, the Company maintains cash balances in financial institutions, which may exceed federally insured limits. The Company has not experienced any losses relating to such accounts and believes it is not exposed to a significant credit risk on its cash and cash equivalents. The Company's accounts receivable arise from revenue arrangements with customers in different countries. The Company's revenue is primarily due to grants made by government-sponsored and private organizations, as well as royalties from our collaboration and license partners. The following entities accounted for more than 10% of total revenue or accounts receivable for the periods presented: Percentage of Revenue Percentage of Accounts Receivable as of December 31, 2021 2020 2019 2021 2020 U.S. government (a) 71 % 46 % 40 % * 78 % CEPI 12 % 47 % * * * BMGF * * 45 % * * SK bioscience, Co., Ltd. 14 % * * * * Gavi, the Vaccine Alliance * * * 77 % * Government of New Zealand * * * * 17 % *Amounts represent less than 10% (a) Including U.S. government partnership formerly known as Operation Warp Speed, Department of Defense, and Biomedical Advanced Research and Development Authority
Pre-Launch Inventory	Pre-Launch Inventory Prior to initial regulatory authorizations for its product candidates, the Company expenses costs relating to raw materials and inventory production as research and development expenses in the consolidated statements of operations, in the period incurred. The Company capitalizes the costs of production as inventory when regulatory authorization and subsequent commercialization are considered probable and the Company expects to realize future economic benefit from the sales of the product candidate. Upon the authorization of distribution and use of NVX-CoV2373 following regulatory authorizations by EMA and the WHO in December 2021, the Company began to capitalize inventory costs associated with the related supply of NVX-CoV2373, as it was determined that inventory costs subsequently incurred had a probable future economic benefit.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. and are depreciated using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance costs are expensed as incurred. The estimated useful lives of property and equipment are described below: Useful Life Buildings 25 years Machinery and equipment 5 - 7 years Computer hardware 3 years Leasehold improvements Shorter of useful life or remaining term of the lease
Leases Accounting	Lease Accounting The Company enters into manufacturing supply agreements with contract manufacturing organizations (“CMO”) and contract development and manufacturing organizations (“CDMO”) to manufacture its vaccine candidates. Certain of these manufacturing supply agreements include the use of identified manufacturing facilities and equipment that are controlled by the Company and for which the Company obtains substantially all the output and may qualify as an embedded lease. The Company treats manufacturing supply agreements that contain a lease as lease arrangements in their entirety. The evaluation of leases that are embedded in the Company’s CMO and CDMO agreements is complex and requires judgment in determining whether the contract, either explicitly or implicitly, is for the use of an identified asset and the Company has the right to direct the use of, and obtain substantially all of the benefit from, the identified asset which generally, is the use of a portion of the manufacturing facility of the CMO or CDMO, whether the Company has the right to direct the use of, and obtain substantially all of the benefit from, the identified asset, the term of the lease, and the fixed lease payments under the contract. Depending on the contract, the lease commencement date, defined as the date on which the lessor makes the underlying asset available for use by the lessee and is the date on which the Company is required to accrue lease expenses, may be different than the inception date of the contract. The Company determines the non-cancellable lease term of its embedded leases based on the impact of certain expected milestones on its option to terminate the lease where it is reasonably certain to not exercise that option. The Company evaluates changes to the terms and conditions of a lease contract to determine if they result in a new lease or a modification of an existing lease. For lease modifications, the Company remeasures and reallocates the remaining consideration in the contract and reassesses the lease classification at the effective date of the modification. Leases are classified as either operating or finance leases based on the economic substance of the agreement. The Company also enters into non-cancelable lease agreements for facilities and certain equipment. For leases that have a lease term of more than 12 months at the lease commencement date, the Company recognizes lease liabilities, which represent the Company’s obligation to make lease payments arising from the lease, and corresponding right-of-use (“ROU”) assets, which represent the right to use an underlying asset for the lease term, based on the present value of the fixed future payments over the lease term. The Company calculates the present value of future payments using the discount rate implicit in the lease, if available, or the Company’s incremental borrowing rate. For all leases that have a lease term of 12 months or less at the commencement date (referred to as “short-term” leases), the Company has elected to apply the practical expedient in ASC Topic 842, Leases (“ASC 842”), to not recognize a lease liability or ROU asset but, instead, recognize lease payments as an expense on a straight-line basis over the lease term and variable lease payments that do not depend on an index or rate as an expense in the period in which the variable lease costs are incurred based on performance or usage in accordance with contractual agreements. In determining the lease period, the Company evaluates facts and circumstances that could affect the period over which it is reasonably certain to use the underlying asset while taking into consideration the non-cancelable period over which it has the right to use the underlying asset and any option period to extend or terminate the lease if it is reasonably certain to exercise the option. The Company re-evaluates short-term leases that are modified and if they no longer meet the requirements to be treated as a short-term lease, recognizes and measures the lease liability and ROU asset as if the date of the modification is the lease commencement date. For short-term leases that are modified and continue to meet the requirements to be treated as a short-term lease, the Company remeasures the fixed lease payments under the modified lease and recognize lease payments as an expense on a straight-line basis over the modified lease term. For operating leases, the Company recognizes lease expense related to fixed payments on a straight-line basis over the lease term and lease expense related to variable payments as incurred based on performance or usage in accordance with the contractual agreements. For finance leases, the Company recognizes the amortization of the ROU asset over the shorter of the lease term or useful life of the underlying asset. The Company expenses ROU assets acquired for research and development activities under ASC Topic 730, Research and Development , if they do not have an alternative future use, in research and development projects or otherwise. The Company uses significant assumptions and judgment in evaluating its lease contracts and other agreements under ASC 842, including the determination of whether an agreement is or contains a lease, whether a change in the terms and conditions of a lease contract represent a new or modified lease, whether a lease represents an operating or finance lease, the discount rate used to determine the present value of lease obligations, and the term of a lease embedded in its manufacturing supply agreements.
Intangible Assets	Intangible Assets The Company’s intangible assets include proprietary adjuvant technology and collaboration agreements, which were measured at the estimated fair values as of their acquisition dates. Amortization expense for intangible assets is recorded on a straight-line basis over the expected useful lives of the assets, ranging from 7 years to 20 years.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets, including property and equipment and finite-lived intangible and right-of-use assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable based on the criteria for accounting for the impairment or disposal of long-lived assets under ASC Topic 360, Property, Plant and Equipment. The Company calculates the estimated fair value of a long-lived asset (group) using the income approach. Impairment losses are recognized when the sum of expected future cash flows is less than the assets’ (group’s) carrying value.
Goodwill	Goodwill Goodwill is subject to impairment tests annually or more frequently should indicators of impairment arise. The Company has determined that, because its only business is the development of recombinant vaccines, it operates as a single operating segment and has one reporting unit. The Company primarily utilizes the market approach and, if considered necessary, the income approach to determine if it has an impairment of its goodwill. The market approach is based on market value of invested capital. To ensure that the Company’s capital stock is the appropriate measurement of fair value, the Company considers factors such as its trading volume, diversity of investors, and analyst coverage. If considered necessary, the income approach is used to corroborate the results of the market approach. Goodwill impairment may exist if the carrying value of the reporting unit exceeds its estimated fair value. If the carrying value of the reporting unit exceeds its fair value, step two of the impairment analysis is performed. In step two of the analysis, an impairment loss is recorded equal to the excess of the carrying value of the reporting unit’s goodwill over its implied fair value, should such a circumstance arise. At October 1, 2021 and 2020, the fair value of the Company’s single reporting unit was substantially higher than its carrying value, resulting in no impairment to goodwill as of October 1, 2021 and 2020.
Revenue Recognition	Revenue Recognition At contract inception, the Company analyzes its revenue arrangements to determine the appropriate accounting under U.S. GAAP. Currently, the Company’s revenue arrangements represent customer contracts within the scope of ASC Topic 606, Revenue from Contracts with Customers (Topic 606) (“ASC 606”), or are subject to the contribution guidance in ASC Topic 958-605, Not-for-Profit Entities – Revenue Recognition (“ASC 958-605”), which applies to business entities that receive contributions within the scope of ASC 958-605. The Company recognizes revenue from arrangements within the scope of ASC 606 following the five-step model: (i) identify the contract(s) with a customer; (ii) identify the performance obligation(s) in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligation(s) in the contract; and (v) recognize revenue when (or as) it satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration it is entitled to in exchange for the goods or services it transfers to its customer. The Company recognizes contribution revenue within the scope of ASC 958-605 when the funder-imposed conditions have been substantially met. Contributions are recorded as deferred revenue until the period in which research and development activities are performed that satisfy the funder-imposed conditions. Grants Grant revenue includes both revenue from government contracts and grants from organizations such as CEPI. The Company performs research and development under government funding, grant, license, and clinical development agreements. The revenue primarily consists of funding under U.S. government contracts and other arrangements to advance the clinical development and manufacturing of NVX-CoV2373. The Company’s U.S. government contracts are with the U.S. Department of Defense (the “DoD”) and the U.S. government partnership formerly known as Operation Warp Speed (“OWS”) (see Note 12). Other funding arrangements primarily include a grant and forgivable loan funding from CEPI (see Note 12). Under the U.S. government contracts, the Company is entitled to receive funding on a cost-reimbursable or cost-reimbursable-plus-fixed-fee basis, to support certain activities related to the development, manufacture, and delivery of NVX-CoV2373 to the U.S. government. The Company analyzed these contracts and determined that they are within the scope of ASC 606. The obligations under each of the contracts are not distinct in the context of the contract as they are highly interdependent or interrelated and, as such, they are accounted for as a single performance obligation. The transaction price under these arrangements is the consideration the Company is expecting to receive and consists of the funded contract amount and the unfunded variable amount to the extent that it is probable that a significant reversal of revenue will not occur. The Company recognizes revenue for these contracts over time as the Company transfers control over the goods and services and satisfies the performance obligation. The Company measures progress toward satisfaction of the performance obligation using an Estimate-at-Completion (“EAC”) process, which is a cost-based input method that reviews and monitors the progress towards the completion of the Company’s performance obligation. Under this process, management considers the costs that have been incurred to-date, as well as projections to completion using various inputs and assumptions, including, but not limited to, progress towards completion, labor costs and level of effort, material and subcontractor costs, indirect administrative costs, and other identified risks. Estimating the total allowable cost at completion of the performance obligation under a contract is subjective and requires the Company to make assumptions about future activity and cost drivers. Changes in these estimates can occur for a variety of reasons and, if significant, may impact the timing of revenue and fee recognition on the Company’s contracts. Allowable contract costs include direct costs incurred on the contract and indirect costs that are applied in the form of rates to the direct costs. Progress billings under the contracts are initially based on provisional indirect billing rates, agreed upon between the Company and the U.S. government. These indirect rates are subject to review on an annual basis. The Company records the impact of changes in the indirect billing rates in the period when such changes are identified. These changes reflect the difference between actual indirect costs incurred compared to the estimated amounts used to determine the provisional indirect billing rates agreed upon with the U.S. government. The Company recognizes revenue on the U.S government contracts based on reimbursable allowable contract costs incurred in the period up to the transaction price. For cost-reimbursable-plus-fixed-fee contracts, the Company recognizes the fixed-fee based on the proportion of reimbursable contract costs incurred to total estimated allowable contract costs expected to be incurred on completion of the underlying performance obligation as determined under the EAC process. The Company recognizes changes in estimates related to the EAC process in the period when such changes are made on a cumulative catch-up basis. The Company includes the transaction price comprising both funded and unfunded portions of customer contracts in this estimate. The Company’s other funding agreements currently include funding from CEPI in the form of a grant (“CEPI Grant Funding”) and one or more forgivable no interest term loans (“CEPI Forgivable Loan Funding”). Under the Company’s grant funding arrangements, currently including the CEPI and BMGF arrangements, the Company is primarily entitled to reimbursement for costs that support development related activities of NVX-CoV2373. The Company analyzed these other funding arrangements and determined that they are not within the scope of ASC 606 as they do not provide a direct economic benefit to the grantor. Payments received under the grant funding arrangements are considered conditional contributions under the scope of ASC 958-605 and are recorded as deferred revenue until the period in which such research and development activities are actually performed in a manner that satisfies the funder-imposed conditions. Payments received under the CEPI Forgivable Loan Funding agreement are only repayable if the proceeds of sales to one or more third parties of NVX-CoV2373 cover the Company’s costs of manufacturing such vaccine candidate, not including manufacturing costs funded by CEPI. As the financial risk remains with CEPI, the Company determined that the use of the funds from the CEPI agreement is outside the scope of ASC Topic 470, Debt . The research and development risk was considered substantive, such that it was not probable that the development would be successful at the inception of the contract. Therefore, the Company concluded that ASC 730 was considered applicable and most appropriate. Given the financial risk associated with the research and development activities lies with CEPI because repayment of any funds provided by CEPI depends solely on the results of the research and development activities having future economic benefit, the Company has accounted for the obligation under the CEPI Forgivable Loan Funding as a contract to perform research and development for others. The Company has determined that payments received under these agreements should be recorded as revenue under ASC 958-605 rather than a reduction to research and development expenses. This is consistent with the Company’s policy of presenting such amounts as revenue. In reaching this determination, the Company considered a number of factors, including whether it is principal under the arrangement, and whether the arrangement is significant to, and part of, the Company’s core operations. The Company will record revenue as it performs the contractual research and development services. Royalties and Other The Company also has various arrangements that include a right for a third party to use the Company's intellectual property as a functional license. These licensing arrangements include sales-based royalties, certain development and commercial milestone payments, and the sale of proprietary Matrix-M TM adjuvant. The license is deemed to be the predominant item to which the sales-based royalties or milestone payments relate. Because development milestone payments are contingent on the achievement of milestones, such as regulatory approvals, that are not within the Company or licensee's control, the payments are not considered probable of being achieved and are excluded from the transaction price until the milestone is achieved. The Company recognizes revenue when the development milestone is achieved. For arrangements that include sales-based royalties, including milestone payments based upon the achievement of a certain level of product sales, wherein the license is deemed to be the sole or predominant item, the Company recognizes revenue on the satisfaction (or partial satisfaction) of the performance obligation, which is when the related sales occur. The Company allocates the transaction price to each performance obligation based on a relative standalone selling price basis. It develops assumptions that require judgment to determine the standalone selling price for each performance obligation in consideration of applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer.
Research and Development Expenses	Research and Development Expenses Research and development expenses include salaries, stock-based compensation, laboratory supplies, consultants and subcontractors, including external contract research organizations (“CROs”), CMOs, and CDMOs and other expenses associated with the Company’s process development, manufacturing, clinical, regulatory, and quality assurance activities for its clinical development programs. In addition, related indirect costs such as fringe benefits and overhead expenses are also included in research and development expenses. The Company estimates its research and development expense related to services performed under its contracts with external service providers based on an estimate of the level of service performed in the period. Research and development activities are expensed as incurred.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company accrues research and development expenses, including clinical trial-related expenses, as the services are performed, which may include estimates of those expenses incurred, but not invoiced. The Company uses information provided by third-party service providers and CROs, CMOs, and CDMOs invoices and internal estimates to determine the progress of work performed on the Company’s behalf. Assumptions based on clinical trial protocols, contracts, and participant enrollment data are also developed to determine and analyze these estimates and accruals. Stock-Based Compensation The Company accounts for stock-based compensation related to grants of stock options, stock appreciation rights, restricted stock awards, and purchases under the Company’s Employee Stock Purchase Plan, as amended and restated (the “ESPP”), at fair value. The Company recognizes compensation expense related to such awards on a straight-line basis over the requisite service period (generally the vesting period) of the equity awards, based on the award's fair value at the grant date. The requisite service period is typically one The expected term of stock options and stock appreciation rights granted is based on the Company’s historical option exercise experience and post-vesting forfeiture experience using the historical expected term from the vesting date, whereas the expected term for purchases under the ESPP is based on the purchase periods included in the offering. The expected volatility is determined using historical volatilities based on stock prices over a look-back period corresponding to the expected term. The risk-free interest rate is determined using the yield available for zero-coupon U.S. government issues with a remaining term equal to the expected term. The Company has never paid a dividend, and as such, the dividend yield is zero, and the Company does not intend to pay dividends in the foreseeable future. See Note 13 for a further discussion on stock-based compensation.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Income Taxes . Under the liability method, deferred income taxes are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled. The effect of changes in tax rates on deferred tax assets and liabilities is recognized in income in the period such changes are enacted. A valuation allowance is established when necessary to reduce net deferred tax assets to the amount expected to be realized. Tax benefits associated with uncertain tax positions are recognized in the period in which one of the following conditions is satisfied: (1) the more likely than not recognition threshold is satisfied; (2) the position is ultimately settled through negotiation or litigation; or (3) the statute of limitations for the taxing authority to examine and challenge the position has expired. Tax benefits associated with an uncertain tax position are reversed in the period in which the more likely than not recognition threshold is no longer satisfied. The Company has historically generated significant federal, state, and foreign tax net operating losses, which may be subject to limitation in future periods. Management has fully reserved the related deferred tax assets with a valuation allowance in the current reporting period as it is more likely than not that the related benefit will not be realized. The Company is currently subject to examination in all open tax years. During the year ended December 31, 2021, the Company recognized $29.2 million in income tax expense related to foreign withholding tax on royalties. During the years ended December 31, 2020 and 2019, the Company recognized no income tax expense.
Net Loss per Share	Net Loss per Share Net loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding for the period. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding after giving consideration to the dilutive effect of certain securities outstanding during the period. At December 31, 2021, 2020, and 2019, the Company had potentially dilutive outstanding stock options, stock appreciation rights, and unvested restricted stock units. The Company has generated a net loss in all periods presented; therefore the basic and diluted net loss per share are the same because the inclusion of the potentially dilutive securities would be anti-dilutive. As of December 31, 2021, the Company's Notes (see Note 8) would have been convertible into approximately 2,385,800 shares of the Company's common stock assuming a common stock price of $136.20 or higher. These shares, after giving effect to the add back of interest expense and unamortized debt issuance costs on the Notes and any shares due to the Company upon settlement of its capped call transactions, are excluded from the computation, as their effect is antidilutive.
Foreign Currency	Foreign CurrencyThe accompanying consolidated financial statements are presented in U.S. dollars. The functional currency of Novavax AB, which is located in Sweden, is the local currency (Swedish Krona) and the functional currency of Novavax CZ, which is located in the Czech Republic, is the local currency (Czech Koruna). The translation of assets and liabilities of Novavax AB and Novavax CZ to U.S. dollars are made at the exchange rate in effect at the consolidated balance sheet date, while equity accounts are translated at historical rates. The translation of the statement of operations data is made at the average exchange rate in effect for the period. The translation of operating cash flow data is made at the average exchange rate in effect for the period, and investing and financing cash flow data is translated at the exchange rate in effect at the date of the underlying transaction. Translation gains and losses are recognized as a component of accumulated other comprehensive income (loss) in the accompanying consolidated balance sheets. The foreign currency translation adjustment balance included in accumulated other comprehensive income (loss) was $(1.4) million and $7.0 million at December 31, 2021 and 2020, respectively.
Segment Information	Segment Information The Company manages its business as one operating segment: the development of recombinant vaccines. The Company does not operate separate lines of business with respect to its vaccine candidates. Accordingly, the Company does not have separately reportable segments as defined by ASC Topic 280, Segment Reporting .
Recent Accounting Pronouncements	Recent Accounting Pronouncements Not Yet Adopted In August 2020, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of cash and cash equivalents	Cash and cash equivalents consist of the following (in thousands): December 31, 2021 2020 Cash $ 96,372 $ 122,312 Money market funds  361,822 96,116 Government-backed securities 266,250 44,250 Treasury securities — 44,052 Corporate debt securities 790,672 246,668 Cash and cash equivalents $ 1,515,116 $ 553,398
Schedule of reconciliation of cash, cash equivalents and restricted cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported in the consolidated balance sheets that sum to the total of the same such amounts shown in the statement of cash flows (in thousands): December 31, 2021 2020 Cash and cash equivalents $ 1,515,116 $ 553,398 Restricted cash current 11,490 93,880 Restricted cash non-current (1) 1,653 1,460 Cash, cash equivalents and restricted cash $ 1,528,259 $ 648,738 (1) Classified as Other non-current assets as of December 31, 2021 and 2020
Schedules of Concentration of Risk	The Company's accounts receivable arise from revenue arrangements with customers in different countries. The Company's revenue is primarily due to grants made by government-sponsored and private organizations, as well as royalties from our collaboration and license partners. The following entities accounted for more than 10% of total revenue or accounts receivable for the periods presented: Percentage of Revenue Percentage of Accounts Receivable as of December 31, 2021 2020 2019 2021 2020 U.S. government (a) 71 % 46 % 40 % * 78 % CEPI 12 % 47 % * * * BMGF * * 45 % * * SK bioscience, Co., Ltd. 14 % * * * * Gavi, the Vaccine Alliance * * * 77 % * Government of New Zealand * * * * 17 % *Amounts represent less than 10% (a) Including U.S. government partnership formerly known as Operation Warp Speed, Department of Defense, and Biomedical Advanced Research and Development Authority
Schedule of Property and Equipment, Net	The estimated useful lives of property and equipment are described below: Useful Life Buildings 25 years Machinery and equipment 5 - 7 years Computer hardware 3 years Leasehold improvements Shorter of useful life or remaining term of the lease Property and equipment is comprised of the following at December 31 (in thousands): December 31, 2021 2020 Land and buildings $ 83,534 $ 79,096 Machinery and equipment 119,998 31,609 Leasehold improvements 10,282 9,684 Computer hardware 9,670 6,126 Construction in progress 35,114 71,232 258,598 197,747 Less: accumulated depreciation (29,902) (17,793) Property and equipment, net $ 228,696 $ 179,954

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of investments classified as available-for-sale	The Company had no marketable securities classified as available-for-sale as of December 31, 2021 as all of the Company's investments were in securities classified as cash and cash equivalents. Marketable securities classified as available-for-sale as of December 31, 2020 were comprised of (in thousands): December 31, 2020 Amortized Cost Gross Unrealized Gross Unrealized Losses Fair Value Treasury securities $ 10,038 $ — $ (2) $ 10,036 Corporate debt securities 127,003 13 (3) 127,013 Agency securities 20,599 1 — 20,600 Total $ 157,640 $ 14 $ (5) $ 157,649

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of fair value hierarchy	The following table represents the estimated fair value of the Company’s financial assets and liabilities (in thousands): Fair Value at December 31, 2021 Fair Value at December 31, 2020 Assets Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Money market funds (1) $ 361,822 $ — $ — $ 96,116 $ — $ — Government-backed securities (1) — 266,250 — — 44,250 — Treasury securities (2) — — — — 54,088 — Corporate debt securities (3) — 790,672 — — 373,681 — Agency securities — — — — 20,600 — Total cash equivalents and marketable securities $ 361,822 $ 1,056,922 $ — $ 96,116 $ 492,619 $ — Liabilities Convertible notes payable $ — $ 447,509 $ — $ — $ 407,238 $ — (1) Classified as cash and cash equivalents as of December 31, 2021 and 2020 (see Note 2). (2) Includes $44,052 classified as cash and cash equivalents as of December 31, 2020 on the consolidated balance sheets. (3) Includes $790,672 and $246,668 classified as cash and cash equivalents as of December 31, 2021 and 2020, respectively, on the consolidated balance sheets.

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Identifiable Intangible Assets	Purchased intangible assets consisted of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Intangible Assets, Net Gross Carrying Amount Accumulated Amortization Intangible Assets, Net Finite-lived intangible assets: Proprietary adjuvant technology $ 8,239 $ (3,469) $ 4,770 $ 9,099 $ (3,374) $ 5,725 Collaboration agreements 3,722 (3,722) — 4,109 (4,109) — Total identifiable intangible assets $ 11,961 $ (7,191) $ 4,770 $ 13,208 $ (7,483) $ 5,725
Schedule of Estimated Amortization Expense	Amortization expense for the years ended December 2021, 2020, and 2019 was $0.4 million, $0.6 million, and $0.7 million, respectively. Estimated amortization expense for existing intangible assets for each of the five succeeding years ending December 31 is as follows (in thousands): Year Amount 2022 $ 412 2023 412 2024 412 2025 412 2026 412
Schedule of Goodwill	The change in the carrying amounts of goodwill was as follows (in thousands): Year Ended December 31, 2021 2020 Beginning balance $ 135,379 $ 51,154 Goodwill resulting from the acquisition of Novavax CZ — 70,662 Currency translation adjustments (3,900) 13,563 Ending balance $ 131,479 $ 135,379

Acquisition of Novavax CZ (Tabl

Acquisition of Novavax CZ (Tables)	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Schedule of Assets Acquired and Liabilities Assumed	The table below summarizes the final allocation of the purchase price based upon the fair values of assets acquired and liabilities assumed (in thousands): May 27, 2020 Prepaid expense and other current assets $ 326 Property and equipment 96,739 Goodwill 70,662 Accounts payable (1,193) Accrued expenses (205) Other non-current liabilities (813) Purchase price, net of cash acquired $ 165,516
Schedule of Business Acquisition, Pro Forma Information	The unaudited pro forma financial information combines the historical results of operations of the Company and Novavax CZ and reflects the application of certain pro forma adjustments (in thousands, except per share amounts): Year Ended December 31, 2020 2019 Revenue $ 475,598 $ 18,662 Net loss (419,896) (142,210) Basic and diluted net loss per share $ (7.04) $ (3.22)

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Schedule of Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases as of December 31, 2021 and 2020 was as follows (in thousands, except weighted-average remaining lease term and discount rate): December 31, Lease Assets and Liabilities Classification 2021 2020 Assets: ROU assets, operating, net Other non-current assets $ 40,123 $ 7,794 Liabilities: Current portion of operating lease liabilities Other current liabilities $ 30,983 $ 3,782 Current portion of finance lease liabilities Current portion of finance lease liabilities 130,533 105,862 Total current lease liabilities $ 161,516 $ 109,644 Non-current portion of operating lease liabilities Other non-current liabilities $ 39,116 $ 10,122 Non-current portion of finance lease liabilities Non-current finance lease liabilities — 40,083 Total non-current lease liabilities $ 39,116 $ 50,205 Weighted-average remaining lease term (years): Operating leases 5.0 4.5 Finance leases 3.7 4.7 Weighted-average discount rate: Operating leases 6.0% 13.8% Finance leases 5.2% 6.4%
Schedule of Operating Lease Expenses	Lease expense for the operating and short-term leases for the years ended December 31, 2021 and 2020 was as follows (in thousands): Year Ended December 31, 2021 2020 Operating lease expense $ 37,027 $ 2,462 Short-term lease expense 468,210 66,805 Variable lease expense 116,435 4,854 Finance lease expense: ROU assets expensed $ 112,528 $ 242,009 Interest expense 7,241 3,097 Total finance lease expense $ 119,769 $ 245,106
Schedule of Supplemental Cash Flow Information of Leases	Supplemental cash flow information related to leases for the year ended December 31, 2021 and 2020 was as follows (in thousands): Year Ended December 31, 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used in operating leases $ 203,991 $ 63,634 Operating cash flows used in finance leases 7,241 3,097 Financing cash flows used in finance leases 127,907 96,065 ROU assets obtained in exchange for operating lease obligations $ 66,682 $ 5,590 ROU assets obtained in exchange for finance lease obligations 112,528 242,009
Schedule of Maturities of Lease Liabilities	As of December 31, 2021, maturities of lease liabilities were as follows (in thousands): Year Amount 2022 $ 166,244 2023 7,104 2024 7,238 2025 7,361 2026 7,344 Thereafter 19,186 Total minimum lease payments 214,477 Less: imputed interest (13,845) Total lease liabilities $ 200,632

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Convertible Notes Payable	Total convertible notes payable consisted of the following at (in thousands): December 31, 2021 2020 Principal amount of Notes $ 325,000 $ 325,000 Unamortized debt issuance costs (1,542) (2,965) Total convertible notes payable $ 323,458 $ 322,035
Schedule of Interest Expense	Interest expense incurred in connection with the Notes consisted of the following (in thousands): Year Ended December 31, 2021 2020 2019 Coupon interest at 3.75% $ 12,188 $ 12,188 $ 12,188 Amortization of debt issuance costs 1,424 1,424 1,424 Total interest expense on Notes $ 13,612 $ 13,612 $ 13,612

Other Financial Information (Ta

Other Financial Information (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following at December 31 (in thousands): December 31, 2021 2020 Prepaid expenses $ 120,029 $ 171,602 Other current assets 53,491 9,662 Prepaid expenses and other current assets $ 173,520 $ 181,264
Schedule of Property and Equipment, Net	The estimated useful lives of property and equipment are described below: Useful Life Buildings 25 years Machinery and equipment 5 - 7 years Computer hardware 3 years Leasehold improvements Shorter of useful life or remaining term of the lease Property and equipment is comprised of the following at December 31 (in thousands): December 31, 2021 2020 Land and buildings $ 83,534 $ 79,096 Machinery and equipment 119,998 31,609 Leasehold improvements 10,282 9,684 Computer hardware 9,670 6,126 Construction in progress 35,114 71,232 258,598 197,747 Less: accumulated depreciation (29,902) (17,793) Property and equipment, net $ 228,696 $ 179,954
Schedule of Accrued Expenses	Accrued expenses consist of the following at December 31 (in thousands): December 31, 2021 2020 Employee benefits and compensation $ 38,419 $ 20,752 Research and development accruals 577,100 99,994 Other accrued expenses 58,212 16,644 Accrued expenses $ 673,731 $ 137,390

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2021
Grants, U.S. Government Contract and Joint Venture [Abstract]
Schedule of Increase (Decrease) In Accounts Receivable, Unbilled Services, and Deferred Revenue	During the year ended December 31, 2021, changes in the Company's accounts receivables and deferred revenue balances were as follows (in thousands): December 31, 2020 Additions Deductions December 31, 2021 Contract receivables: Accounts receivable $ 262,012 2,432,268 (2,239,287) $ 454,993 Contract liabilities Deferred revenue (1) $ 273,228 1,598,152 (275,908) $ 1,595,472 (1) Amount is comprised of $1.4 billion of current Deferred revenue and $172.5 million of non-current Deferred revenue.
Schedule of Grant Revenue	The Company recognized grant revenue as follows (in thousands): Year Ended December 31, 2021 2020 U.S. government partnership (a) $ 788,953 $ 204,727 U.S. DoD 21,683 12,519 CEPI 135,445 223,158 BMGF 2,628 12,806 Total grant revenue $ 948,709 $ 453,210 (a) U.S. government partnership formerly known as OWS

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Stock-Based Compensation Expense	The Company recorded stock-based compensation expense in the consolidated statements of operations as follows (in thousands): Year Ended December 31, 2021 2020 2019 Research and development $ 86,928 $ 55,955 $ 8,436 General and administrative 96,698 72,080 8,612 Total stock-based compensation expense $ 183,626 $ 128,035 $ 17,048
Schedule of Option and Appreciation Rights Activity	The following is a summary of stock options and stock appreciation rights activity under the 2015 Plan and the 2005 Plan for the year ended December 31, 2021: 2015 Plan 2005 Plan Stock Options Weighted- Stock Weighted- Outstanding at January 1, 2021 5,420,463 $ 38.05 214,186 $ 88.11 Granted 81,959 $ 177.84 — $ — Exercised (1,778,688) $ 31.11 (145,961) $ 78.11 Canceled (87,897) $ 120.62 — $ — Outstanding at December 31, 2021 3,635,837 $ 42.60 68,225 $ 109.52 Shares exercisable at December 31, 2021 1,170,259 $ 57.01 68,225 $ 109.52 Shares available for grant at December 31, 2021 3,716,636
Schedule of Assumptions Used in Estimation of Fair Value of Stock	The fair value of stock options granted under the 2015 Plan was estimated at the date of grant or the date upon which the 2015 Plan was approved by the Company’s stockholders for certain stock options granted in 2020 and 2019 using the Black-Scholes option-pricing model with the following assumptions: Year Ended December 31, 2021 2020 2019 Weighted average Black-Scholes fair value of stock $158.02 $80.48 $4.98 Risk-free interest rate 0.5%-1.3% 0.2%-1.5% 1.5%-2.6% Dividend yield —% —% —% Volatility 124.7%-142.0% 116.0%-152.2% 105.4%-134.1% Expected term (in years) 4.1-6.1 3.9-7.6 3.9-7.5 The ESPP is considered compensatory for financial reporting purposes. As such, the fair value of ESPP shares was estimated at the date of grant using the Black-Scholes option-pricing model with the following assumptions: Year Ended December 31, 2021 2020 2019 Range of Black-Scholes fair values of ESPP $83.47-$238.85 $2.57-$92.67 $2.57-$35.00 Risk-free interest rate 0.1%-0.2% 0.2%-2.6% 1.2%-2.6% Dividend yield —% —% —% Volatility 114.9%-159.4% 66.6%-189.7% 52.2%-171.6% Expected term (in years) 0.5-2.0 0.5-2.0 0.5-2.0
Schedule of Restricted Stock Units Activity	The following is a summary of restricted stock units activity for the year ended December 31, 2021: Number of Per Share Outstanding and unvested at January 1, 2021 1,044,980 $ 72.59 Restricted stock units granted 316,571 $ 191.82 Restricted stock units vested (488,370) $ 69.02 Restricted stock units forfeited (53,353) $ 141.01 Outstanding and unvested at December 31, 2021 819,828 $ 116.70

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Company's Loss from Operations Before Income Tax Expense by Jurisdiction	The Company’s income (loss) from operations before income tax expense by jurisdiction for the years ended December 31 are as follows (in thousands): Year Ended December 31, 2021 2020 2019 Domestic $ (1,633,016) $ (455,253) $ (124,189) Foreign (81,520) 36,994 (8,505) Loss before income tax expense $ (1,714,536) $ (418,259) $ (132,694)
Schedule of Tax Rate Differences	A reconciliation of the provision for income tax to the amount computed by applying the U.S. federal statutory tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2021 2020 2019 Statutory federal tax rate (21) % (21) % (21) % State income taxes, net of federal benefit (6) % (3) % (2) % Research and development and other tax credits (1) % — % (3) % Non-deductible expenses 2 % 4 % — % Non-cash stock-based compensation (4) % (7) % — % Foreign tax expense 1 % — % — % Other 1 % 1 % 1 % Change in tax rate — % (5) % 3 % Change in valuation allowance 30 % 31 % 22 % Income tax provision 2 % — % — %
Schedule of Deferred Tax Assets (Liabilities)	The significant components of the Company’s deferred tax assets and liabilities as of December 31 were as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforward $ 845,731 $ 325,655 Foreign net operating loss carryforward 25,625 8,620 Research tax credits 44,618 35,065 Lease liability 52,852 39,548 Deferred revenue 20,262 60,657 Non-cash stock-based compensation 24,698 22,577 Original discount interest 1,729 3,177 Other 11,801 12,019 Total deferred tax assets 1,027,316 507,318 Valuation allowance (1,015,333) (504,788) Net deferred tax assets $ 11,983 $ 2,530 Deferred tax liabilities: ROU assets (10,071) (1,253) Intangibles (1,034) (1,198) Other (878) (79) Total deferred tax liabilities $ (11,983) $ (2,530) Net deferred tax assets $ — $ —
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amounts of unrecognized tax benefits in the year ended December 31, 2021, 2020, and 2019 is as follows (in thousands): Year Ended December 31, 2021 2020 2019 Unrecognized tax benefits balance at January 1, $ 8,766 $ — $ — Additions for tax positions of current year 4,158 1,413 — Additions for tax positions of prior years — 7,353 — Reductions for tax positions of prior year (1,770) — — Settlements of tax positions of prior years — — — Unrecognized tax benefits balance at December 31, $ 11,154 $ 8,766 $ —

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	Oct. 01, 2021USD ($)	Oct. 01, 2020USD ($)	Dec. 31, 2021USD ($)segmentreportingUnit$ / sharesshares	Dec. 31, 2020USD ($)
Summary of Significant Accounting Policies [Line Items]
Restricted cash			$ 11,490,000	$ 93,880,000
Number of reporting units | reportingUnit			1
Impairment to goodwill	$ 0	$ 0
Current foreign tax expense (benefit)			$ 29,200,000
Foreign currency translation adjustment			$ (1,400,000)	7,000,000
Number of operating segments | segment			1
Coalition for Epidemic Preparedness Innovations ("CEPI")
Summary of Significant Accounting Policies [Line Items]
Restricted cash			$ 10,400,000	$ 92,400,000
Convertible Debt Securities
Summary of Significant Accounting Policies [Line Items]
Number of shares issued for debt converted (in shares) | shares			2,385,800
Debt instrument, convertible, conversion price (in usd per share) | $ / shares			$ 136.20
Maximum
Summary of Significant Accounting Policies [Line Items]
Intangible assets useful life			20 years
Vesting period			4 years
Minimum
Summary of Significant Accounting Policies [Line Items]
Intangible assets useful life			7 years
Vesting period			1 year

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Reclassification (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Total revenue	$ 1,146,290	$ 475,598	$ 18,662
Reclassification [Line Items]
Total revenue	1,146,290	475,598	18,662
Government Contract | Revision of Prior Period, Adjustment
Accounting Policies [Abstract]
Total revenue		217,200	7,500
Reclassification [Line Items]
Total revenue		217,200	7,500
Grants
Accounting Policies [Abstract]
Total revenue	948,709	453,210	15,937
Reclassification [Line Items]
Total revenue	948,709	453,210	15,937
Grants | Revision of Prior Period, Adjustment
Accounting Policies [Abstract]
Total revenue		236,000	8,400
Reclassification [Line Items]
Total revenue		236,000	8,400
Royalties and other
Accounting Policies [Abstract]
Total revenue	197,581	22,388	2,725
Reclassification [Line Items]
Total revenue	$ 197,581	22,388	2,725
Royalties and other | Revision of Prior Period, Adjustment
Accounting Policies [Abstract]
Total revenue		22,400	2,700
Reclassification [Line Items]
Total revenue		$ 22,400	$ 2,700

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 1,515,116	$ 553,398
Cash
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	96,372	122,312
Money market funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	361,822	96,116
Government-backed securities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	266,250	44,250
Treasury securities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	0	44,052
Corporate debt securities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 790,672	$ 246,668

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Concentration Risk (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue Benchmark | U.S. government
Concentration Risk [Line Items]
Concentration risk, percentage	71.00%	46.00%	40.00%
Revenue Benchmark | CEPI
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	47.00%
Revenue Benchmark | BMGF
Concentration Risk [Line Items]
Concentration risk, percentage			45.00%
Revenue Benchmark | SK bioscience, Co., Ltd.
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%
Accounts Receivable | U.S. government
Concentration Risk [Line Items]
Concentration risk, percentage		78.00%
Accounts Receivable | Gavi, the Vaccine Alliance
Concentration Risk [Line Items]
Concentration risk, percentage	77.00%
Accounts Receivable | Government of New Zealand
Concentration Risk [Line Items]
Concentration risk, percentage		17.00%

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Building
Property, Plant and Equipment [Line Items]
Property and equipment useful life	25 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life	7 years
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life	5 years
Computer Equipment
Property, Plant and Equipment [Line Items]
Property and equipment useful life	3 years

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Reconciliation of cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Cash and cash equivalents	$ 1,515,116	$ 553,398
Restricted cash current	11,490	93,880
Restricted cash, noncurrent	1,653	1,460
Cash, cash equivalents and restricted cash	$ 1,528,259	$ 648,738	$ 82,180	$ 81,959

Marketable Securities (Details)

Marketable Securities (Details) $ in Thousands	Dec. 31, 2020USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 157,640
Gross Unrealized Gains	14
Gross Unrealized Losses	(5)
Fair Value	157,649
Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,038
Gross Unrealized Gains	0
Gross Unrealized Losses	(2)
Fair Value	10,036
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	127,003
Gross Unrealized Gains	13
Gross Unrealized Losses	(3)
Fair Value	127,013
Agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	20,599
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	$ 20,600

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Liabilities
Cash and cash equivalents	$ 1,515,116	$ 553,398
Treasury securities
Liabilities
Cash and cash equivalents		44,052
Corporate debt securities
Liabilities
Cash and cash equivalents	790,672	246,668
Level 1
Assets
Total cash equivalents and marketable securities	361,822	96,116
Liabilities
Convertible notes payable	0	0
Level 1 | Money market funds
Assets
Total cash equivalents and marketable securities	361,822	96,116
Level 1 | Government-backed securities
Assets
Total cash equivalents and marketable securities	0	0
Level 1 | Treasury securities
Assets
Total cash equivalents and marketable securities	0	0
Level 1 | Corporate debt securities
Assets
Total cash equivalents and marketable securities	0	0
Level 1 | Agency securities
Assets
Total cash equivalents and marketable securities	0	0
Level 2
Assets
Total cash equivalents and marketable securities	1,056,922	492,619
Liabilities
Convertible notes payable	447,509	407,238
Level 2 | Money market funds
Assets
Total cash equivalents and marketable securities	0	0
Level 2 | Government-backed securities
Assets
Total cash equivalents and marketable securities	266,250	44,250
Level 2 | Treasury securities
Assets
Total cash equivalents and marketable securities	0	54,088
Level 2 | Corporate debt securities
Assets
Total cash equivalents and marketable securities	790,672	373,681
Level 2 | Agency securities
Assets
Total cash equivalents and marketable securities	0	20,600
Level 3
Assets
Total cash equivalents and marketable securities	0	0
Liabilities
Convertible notes payable	0	0
Level 3 | Money market funds
Assets
Total cash equivalents and marketable securities	0	0
Level 3 | Government-backed securities
Assets
Total cash equivalents and marketable securities	0	0
Level 3 | Treasury securities
Assets
Total cash equivalents and marketable securities	0	0
Level 3 | Corporate debt securities
Assets
Total cash equivalents and marketable securities	0	0
Level 3 | Agency securities
Assets
Total cash equivalents and marketable securities	$ 0	$ 0

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 11,961	$ 13,208
Accumulated Amortization	(7,191)	(7,483)
Intangible Assets, Net	4,770	5,725
Proprietary adjuvant technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,239	9,099
Accumulated Amortization	(3,469)	(3,374)
Intangible Assets, Net	4,770	5,725
Collaboration agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,722	4,109
Accumulated Amortization	(3,722)	(4,109)
Intangible Assets, Net	$ 0	$ 0

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 0.4	$ 0.6	$ 0.7

Intangible Assets and Goodwil_4

Intangible Assets and Goodwill - Schedule of Estimated Amortization Expense (Details) $ in Thousands	Dec. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 412
2023	412
2024	412
2025	412
2026	$ 412

Intangible Assets and Goodwil_5

Intangible Assets and Goodwill - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 135,379	$ 51,154
Goodwill resulting from the acquisition of Novavax CZ	0	70,662
Currency translation adjustments	(3,900)	13,563
Goodwill, ending balance	$ 131,479	$ 135,379

Acquisition of Novavax CZ - Add

Acquisition of Novavax CZ - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	May 27, 2020	Dec. 31, 2019
Business Combination Segment Allocation [Line Items]
Goodwill	$ 131,479	$ 135,379		$ 51,154
Novavax CZ
Business Combination Segment Allocation [Line Items]
Goodwill			$ 70,662
Loss on acquiree since acquisition date		11,300
Business combination, acquisition related costs		$ 2,700
Novavax CZ | Minimum
Business Combination Segment Allocation [Line Items]
Property and equipment useful life		4 years
Novavax CZ | Maximum
Business Combination Segment Allocation [Line Items]
Property and equipment useful life	25 years

Acquisition of Novavax CZ - Sch

Acquisition of Novavax CZ - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	May 27, 2020	Dec. 31, 2019
Business Combination Segment Allocation [Line Items]
Goodwill	$ 131,479	$ 135,379		$ 51,154
Novavax CZ
Business Combination Segment Allocation [Line Items]
Prepaid expense and other current assets			$ 326
Property and equipment			96,739
Goodwill			70,662
Accounts payable			(1,193)
Accrued expenses			(205)
Other non-current liabilities			(813)
Purchase price, net of cash acquired			$ 165,516

Acquisition of Novavax CZ - S_2

Acquisition of Novavax CZ - Schedule of Business Acquisition, Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Combinations [Abstract]
Revenue	$ 475,598	$ 18,662
Net loss	$ (419,896)	$ (142,210)
Basic net loss per share (in usd per share)	$ (7.04)	$ (3.22)
Diluted net loss per share (in usd per share)	$ (7.04)	$ (3.22)

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)ft²	Dec. 31, 2020USD ($)
Lessee, Lease, Description [Line Items]
ROU assets obtained in exchange for operating lease obligations	$ 66,682	$ 5,590
CMO and CMD Agreements
Lessee, Lease, Description [Line Items]
Lease liability and right of use assets recognized	$ 144,400	$ 245,900
700Q0 Agreement
Lessee, Lease, Description [Line Items]
Facility, number of square feet | ft²	170,000
Operating lease expiration		15 years
Operating lease, expense	$ 5,800
Payments for tenant improvements	36,400
Payments for (proceeds from) tenant allowance	$ 30,600
Minimum | Facility Lease Agreement
Lessee, Lease, Description [Line Items]
Operating lease expiration	3 years
Maximum | Facility Lease Agreement
Lessee, Lease, Description [Line Items]
Operating lease expiration	9 years

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
ROU assets, operating, net	$ 40,123	$ 7,794
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent	Other Assets, Noncurrent
Current portion of operating lease liabilities	$ 30,983	$ 3,782
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Current portion of finance lease liabilities	$ 130,533	$ 105,862
Total current lease liabilities	161,516	109,644
Non-current portion of operating lease liabilities	$ 39,116	$ 10,122
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other non-current liabilities	Other non-current liabilities
Non-current finance lease liabilities	$ 0	$ 40,083
Total non-current lease liabilities	$ 39,116	$ 50,205
Weighted average remaining term, operating lease	5 years	4 years 6 months
Weighted average remaining lease term, finance lease	3 years 8 months 12 days	4 years 8 months 12 days
Weighted average discount rate, operating lease	6.00%	13.80%
Weighted average discount rate, finance lease	5.20%	6.40%

Leases - Schedule of Operating

Leases - Schedule of Operating Lease Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease expense	$ 37,027	$ 2,462
Short-term lease expense	468,210	66,805
Variable lease expense	116,435	4,854
ROU assets expensed	112,528	242,009
Interest expense	7,241	3,097
Total finance lease expense	$ 119,769	$ 245,106

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Cash Flow Information of Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating cash flows used in operating leases	$ 203,991	$ 63,634
Operating cash flows used in finance leases	7,241	3,097
Financing cash flows used in finance leases	127,907	96,065	$ 0
ROU assets obtained in exchange for operating lease obligations	66,682	5,590
ROU assets obtained in exchange for finance lease obligations	$ 112,528	$ 242,009

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Dec. 31, 2021USD ($)
Leases [Abstract]
2022	$ 166,244
2023	7,104
2024	7,238
2025	7,361
2026	7,344
Thereafter	19,186
Total minimum lease payments	214,477
Less: imputed interest	(13,845)
Total current lease liabilities	$ 200,632

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details)	Mar. 31, 2017shares	Mar. 16, 2016USD ($)	Mar. 31, 2017USD ($)$ / shares	Mar. 31, 2016USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Jan. 25, 2016$ / shares
Debt Instrument [Line Items]
Reverse stock split conversion ratio					0.05
Aggregate principal amount of notes issued					$ 325,000,000	$ 325,000,000
Coupon interest rate				3.75%
Sale of stock (in usd per share) | $ / shares							$ 111.20
Debt issuance costs				$ 10,000,000
Debt instrument, term				7 years
Call Option
Debt Instrument [Line Items]
Conversion premium percentage							75.00%
Payment for capped call transactions				$ 38,500,000
Debt cap price (in usd per share) | $ / shares							194.60
Debt issuance costs				900,000
Unsecured Debt
Debt Instrument [Line Items]
Convertible debt conversion rate | $ / shares			0.073411
Aggregate principal amount of notes issued				$ 325,000,000
Net proceeds received		$ 315,000,000
Number of shares issued for debt converted (in shares) | shares	2,385,800
Debt instrument, convertible, conversion price (in usd per share) | $ / shares							$ 136.20
Conversion premium percentage							22.50%
Unsecured Debt | Maximum
Debt Instrument [Line Items]
Convertible debt conversion rate			0.089928

Long-Term Debt - Schedule of No

Long-Term Debt - Schedule of Notes Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Principal amount of Notes	$ 325,000	$ 325,000
Unamortized debt issuance costs	(1,542)	(2,965)
Total convertible notes payable	$ 323,458	$ 322,035

Long-Term Debt - Schedule of In

Long-Term Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2016
Debt Disclosure [Abstract]
Coupon interest at 3.75%	$ 12,188	$ 12,188	$ 12,188
Amortization of debt issuance costs	1,424	1,424	1,424
Total interest expense on Notes	$ 13,612	$ 13,612	$ 13,612
Coupon interest rate				3.75%

Preferred Stock (Details)

Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)		0	0	0
Preferred stock, par or stated value per share (in usd per share)		$ 0.01	$ 0.01	$ 0.01
Shares issued (in usd per share)	$ 455.70
Proceeds from issuance of preferred stock			$ 0	$ 199,822	$ 0
Preferred stock beneficial conversion feature				0
Additional Paid-in Capital
Class of Stock [Line Items]
Reclassification from preferred stock to additional paid in capital		$ 199,800
Preferred stock beneficial conversion feature		$ 24,100		$ 24,139
Private Placement
Class of Stock [Line Items]
Preferred stock, par or stated value per share (in usd per share)		$ 0.01		$ 0.01
Series A Preferred Stock | Private Placement
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	438,885
Preferred stock, par or stated value per share (in usd per share)		$ 0.01		$ 0.01
Redeemable Convertible Preferred Stock | Private Placement
Class of Stock [Line Items]
Proceeds from issuance of preferred stock	$ 200,000
Shares issued upon conversion (shares issued)		4,388,850		4,388,850

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock, net of issuance costs		$ 564,859	$ 878,850	$ 97,890
Private Placement
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock, net of issuance costs			877,000
Common Stock
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock, net of issuance costs	$ 500,000	$ 26	$ 324	$ 130
Shares sold (in shares)		2,578,967	32,393,438	12,980,177

Other Financial Information - A

Other Financial Information - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, net	$ 228,696	$ 179,954
Depreciation expense	12,500	$ 4,300	$ 5,100
Czech Republic
Property, Plant and Equipment [Line Items]
Property and equipment, net	$ 168,000

Other Financial Information - S

Other Financial Information - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid expenses	$ 120,029	$ 171,602
Other current assets	53,491	9,662
Prepaid expenses and other current assets	$ 173,520	$ 181,264

Other Financial Information -_2

Other Financial Information - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment	$ 258,598	$ 197,747
Less: accumulated depreciation	(29,902)	(17,793)
Property and equipment, net	228,696	179,954
Land and buildings
Property, Plant and Equipment [Line Items]
Property and equipment	83,534	79,096
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment	119,998	31,609
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	10,282	9,684
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment	9,670	6,126
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment	$ 35,114	$ 71,232

Other Financial Information -_3

Other Financial Information - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Employee benefits and compensation	$ 38,419	$ 20,752
Research and development accruals	577,100	99,994
Other accrued expenses	58,212	16,644
Accrued expenses	$ 673,731	$ 137,390

Revenue - Narrative (Details)

Revenue - Narrative (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Jul. 31, 2020USD ($)dose	Jun. 30, 2020USD ($)dose	Sep. 30, 2015USD ($)	Dec. 31, 2021USD ($)dosesegment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2021USD ($)dose	Aug. 31, 2021USD ($)	Feb. 28, 2021dose
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Billed contracts receivable				$ 419,700	$ 262,000
Unbilled contracts receivable				35,300	0
Revenue from contract with customer			$ 89,100
Total revenue				1,146,290	475,598	$ 18,662
Deferred revenue				1,600,000	45,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation to be satisfied				$ 8,000,000
Remaining performance obligation, expected timing of satisfaction, period				1 year
Sales-Based Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue				$ 178,600
U.S. government partnership
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses | dose	100,000,000
Research and development arrangement, , increase (decrease) in contract ceiling								$ 52,900
Research and development arrangement, contract ceiling							$ 1,800,000
U.S. government partnership | Government Contract
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from contract with customer	$ 1,750,000			1,000,000
Research and development arrangement, contract to perform for others, contract remaining				$ 800,000
Global Access Commitments Agreement GACA
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Contract term				15 years
Contract term after first sale				10 years
Contract term additional years				5 years
BMGF | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Grant agreement	$ 15,000
Coalition for Epidemic Preparedness Innovations ("CEPI")
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Contract to perform for others funding				$ 399,500
Contract to perform for others grant				257,000
Contract to perform for others forgivable no interest term loans				142,500
DoD Contract
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses | dose		10,000,000
DoD Contract | Government Contract
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from contract with customer		$ 45,700
Takeda Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | dose							150,000,000
Potential future milestone payments				$ 20,000
Revenue					$ 20,000
Gavi Advance Purchase Agreement SIIPL
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | dose				1,100,000,000
Contract with customer, liability				$ 350,000
Remaining performance obligation, variable consideration amount				$ 350,000
Gavi Advance Purchase Agreement- COVAX Facility
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | dose				350,000,000
European Commissions ("EC")
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | segment				100,000,000
Additional purchase option, number of doses | segment				200,000,000
European Commissions ("EC") | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | segment				100,000,000
European Commissions ("EC") | Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | segment				20,000,000
SK Bioscience Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | dose									40,000,000

Revenue - Accounts Receivable (

Revenue - Accounts Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounts receivable
Accounts receivable, beginning balance	$ 262,012
Additions	2,432,268
Deductions	(2,239,287)
Accounts receivable, ending balance	454,993
Deferred Revenue Increase (Decrease) [Abstract]
Deferred revenue, beginning balance	273,228
Additions	1,598,152
Deductions	(275,908)
Deferred revenue, ending balance	1,595,472
Deferred revenue, current	1,422,944	$ 273,228
Deferred revenue, noncurrent	$ 172,528	$ 0

Revenue - Schedule of Grant Rev

Revenue - Schedule of Grant Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue	$ 1,146,290	$ 475,598	$ 18,662
Grants
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue	948,709	453,210	$ 15,937
Grants | U.S. government partnership
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue	788,953	204,727
Grants | US Department of Defense ("DoD Contract")
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue	21,683	12,519
Grants | Coalition For Epidemic Preparedness Innovations Award
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue	135,445	223,158
Grants | BMGF
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenue	$ 2,628	$ 12,806

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of stock options and stock appreciation rights exercised		$ 453.8	$ 187.3	$ 0.5
Unrecognized compensation expense		$ 190
Unrecognized compensation expense, recognition period		1 year 2 months 12 days
Aggregate intrinsic value of stock options and stock appreciation rights outstanding		$ 376
Weighted-average remaining contractual term of stock options and stock appreciation rights outstanding		7 years 8 months 12 days
Aggregate intrinsic value of stock options and stock appreciation rights exercisable			$ 108
Weighted-average remaining contractual term of stock options and stock appreciation rights exercisable			6 years 9 months 18 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proposal to increase authorized shares (in shares)		600,000
Maximum contribution of employees as payroll deductions		15.00%
Percentage of market price for stock purchase		85.00%
Shares available for grant		164,495
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance (in shares)		12,400,000
Proposal to increase authorized shares (in shares)		1,500,000
Minimum grant price, percent of common stock fair value	100.00%
Stock options granted (in shares)		81,959
Granted (in usd per share)		$ 177.84
Share-based payment award, terms of award	10 years
Shares available for grant		3,716,636
2005 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)		0
Granted (in usd per share)		$ 0
2005 Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
2005 Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 183,626	$ 128,035	$ 17,048
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	86,928	55,955	8,436
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 96,698	$ 72,080	$ 8,612

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Option and Appreciation Rights Activity (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
2015 Plan
Stock Options
Outstanding (in shares)	5,420,463
Granted (in shares)	81,959
Exercised (in shares)	(1,778,688)
Canceled (in shares)	(87,897)
Outstanding (in shares)	3,635,837
Shares exercisable (in shares)	1,170,259
Shares available for grant (in shares)	3,716,636
Weighted Average Exercise Price (in usd per share)
Outstanding at beginning of year (in usd per share) | $ / shares	$ 38.05
Granted (in usd per share) | $ / shares	177.84
Exercised (in usd per share) | $ / shares	31.11
Canceled (in usd per share) | $ / shares	120.62
Outstanding at end of year (in usd per share) | $ / shares	42.60
Shares exercisable at end of year (in usd per share) | $ / shares	$ 57.01
2005 Plan
Stock Options
Outstanding (in shares)	214,186
Granted (in shares)	0
Exercised (in shares)	(145,961)
Canceled (in shares)	0
Outstanding (in shares)	68,225
Shares exercisable (in shares)	68,225
Weighted Average Exercise Price (in usd per share)
Outstanding at beginning of year (in usd per share) | $ / shares	$ 88.11
Granted (in usd per share) | $ / shares	0
Exercised (in usd per share) | $ / shares	78.11
Canceled (in usd per share) | $ / shares	0
Outstanding at end of year (in usd per share) | $ / shares	109.52
Shares exercisable at end of year (in usd per share) | $ / shares	$ 109.52

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Assumptions Used in Estimation of Fair Value of Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Black-Scholes fair value (in usd per share)	$ 158.02	$ 80.48	$ 4.98
Risk-free interest rate, minimum	0.50%	0.20%	1.50%
Risk-free interest rate, maximum	1.30%	1.50%	2.60%
Dividend yield	0.00%	0.00%	0.00%
Volatility, minimum	124.70%	116.00%	105.40%
Volatility, maximum	142.00%	152.20%	134.10%
Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	4 years 1 month 6 days	3 years 10 months 24 days	3 years 10 months 24 days
Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	7 years 7 months 6 days	7 years 6 months
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	0.10%	0.20%	1.20%
Risk-free interest rate, maximum	0.20%	2.60%	2.60%
Dividend yield	0.00%	0.00%	0.00%
Volatility, minimum	114.90%	66.60%	52.20%
Volatility, maximum	159.40%	189.70%	171.60%
ESPP | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Black-Scholes fair value (in usd per share)	$ 83.47	$ 2.57	$ 2.57
Expected term (in years)	6 months	6 months	6 months
ESPP | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Black-Scholes fair value (in usd per share)	$ 238.85	$ 92.67	$ 35
Expected term (in years)	2 years	2 years	2 years

Stock-Based Compensation - Sc_4

Stock-Based Compensation - Schedule of Restricted Stock Units Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Number of Shares
Outstanding and unvested beginning of year (in shares) | shares	1,044,980
Restricted stock units granted (in shares) | shares	316,571
Restricted stock units vested (in shares) | shares	(488,370)
Restricted stock cancelled (in shares) | shares	(53,353)
Outstanding and unvested at end of year (in shares) | shares	819,828
Per Share Weighted-Average Grant-Date Fair Value (in usd per share)
Outstanding and unvested at beginning of year (in shares) | $ / shares	$ 72.59
Restricted stock units granted (in usd per share) | $ / shares	191.82
Restricted stock units vested (in usd per share) | $ / shares	69.02
Restricted stock units forfeited (in usd per share) | $ / shares	141.01
Outstanding and unvested at end of year (in shares) | $ / shares	$ 116.70

Employee Benefits (Details)

Employee Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
United States
Defined Benefit Plan Disclosure [Line Items]
Maximum contribution, percentage of compensation	100.00%
Defined contribution plan, employer matching contribution, percent of match	4.00%
Defined contribution plan, cost	$ 3.4	$ 0.9	$ 1
Foreign Plan | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost	$ 1.7	$ 1	$ 0.7
First Three Percent Of Participants Deferral | United States
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	100.00%
Defined contribution plan, employer matching contribution, percent of match	3.00%
Next Two Percent Of Participants Deferral | United States
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	50.00%
Defined contribution plan, employer matching contribution, percent of match	2.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Tax Credit Carryforward [Line Items]
Income tax expense	$ 29,215	$ 0	$ 0
Valuation allowance, deferred tax asset, amount increase (decrease)	510,500	139,000
Deferred tax assets	1,027,316	$ 507,318
Unrecognized tax benefits that would impact effective tax rate	11,200
Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	44,600
Domestic
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	3,200,000
Domestic | Subject to Expiration
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	900,000
Domestic | No Expiration
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	2,300,000
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	2,800,000
Foreign
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	$ 127,600

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Company's Loss from Operations Before Income Tax Expense by Jurisdiction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Domestic	$ (1,633,016)	$ (455,253)	$ (124,189)
Foreign	(81,520)	36,994	(8,505)
Loss before income tax expense	$ (1,714,536)	$ (418,259)	$ (132,694)

Income Taxes - Schedule of Tax

Income Taxes - Schedule of Tax Rate Differences (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory federal tax rate	(21.00%)	(21.00%)	(21.00%)
State income taxes, net of federal benefit	(6.00%)	(3.00%)	(2.00%)
Research and development and other tax credits	(1.00%)	0.00%	(3.00%)
Non-deductible expenses	2.00%	4.00%	0.00%
Non-cash stock-based compensation	(4.00%)	(7.00%)	0.00%
Foreign tax expense	1.00%	0.00%	0.00%
Other	1.00%	1.00%	1.00%
Change in tax rate	0.00%	(5.00%)	3.00%
Change in valuation allowance	30.00%	31.00%	22.00%
Income tax provision	2.00%	0.00%	0.00%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Federal and state net operating loss carryforward	$ 845,731	$ 325,655
Foreign net operating loss carryforward	25,625	8,620
Research tax credits	44,618	35,065
Lease liability	52,852	39,548
Deferred revenue	20,262	60,657
Non-cash stock-based compensation	24,698	22,577
Original discount interest	1,729	3,177
Other	11,801	12,019
Total deferred tax assets	1,027,316	507,318
Valuation allowance	(1,015,333)	(504,788)
Net deferred tax assets	11,983	2,530
Deferred tax liabilities:
ROU assets	(10,071)	(1,253)
Intangibles	(1,034)	(1,198)
Other	(878)	(79)
Total deferred tax liabilities	(11,983)	(2,530)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tac Benefits Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits balance at January 1,	$ 8,766	$ 0
Additions for tax positions of current year	4,158	1,413	$ 0
Additions for tax positions of prior years	0	7,353	0
Reductions for tax positions of prior year	(1,770)	0	0
Settlements of tax positions of prior years	0	0	0
Unrecognized tax benefits balance at December 31,	$ 11,154	$ 8,766	$ 0

Related Party Transaction (Deta

Related Party Transaction (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Common stock, shares issued (in shares)		76,433,151	71,350,365
Shares issued (in usd per share)	$ 455.70
Net proceeds from sales of common stock		$ 564,859	$ 875,623	$ 97,392
Director
Related Party Transaction [Line Items]
Common stock, shares issued (in shares)	32,916
Shares issued (in usd per share)	$ 45.57
Net proceeds from sales of common stock	$ 1,500

Commitment and Contingencies (D

Commitment and Contingencies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Purchase obligation		$ 0
Long-term purchase commitment	$ 117,000,000

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended	12 Months Ended
	Jan. 31, 2022	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Issuance of common stock, net of issuance costs			$ 564,859	$ 878,850	$ 97,890
Common Stock
Subsequent Event [Line Items]
Issuance of common stock, net of issuance costs (in shares)			2,578,967	32,393,438	12,980,177
Issuance of common stock, net of issuance costs		$ 500,000	$ 26	$ 324	$ 130
June 2021 Sales Agreement | Common Stock
Subsequent Event [Line Items]
Remaining unissued capital			$ 464,900
Subsequent Event | June 2021 Sales Agreement | Common Stock
Subsequent Event [Line Items]
Issuance of common stock, net of issuance costs (in shares)	400,000
Issuance of common stock, net of issuance costs	$ 34,700