Novavax (NVAX) 10-Q 10 May 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	Apr. 30, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
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	700 Quince Orchard Road,
Entity Address, City or Town	Gaithersburg,
Entity Address, Country	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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		140,403,554
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001000694
Current Fiscal Year End Date	--12-31

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Revenues	$ 93,855	$ 80,951
Expenses:
Cost of sales	59,209	34,086
Research and development	92,679	247,101
Selling, general, and administrative	86,798	112,532
Total expenses	238,686	393,719
Loss from operations	(144,831)	(312,768)
Other income (expense):
Interest expense	(4,111)	(4,316)
Other income	3,654	24,362
Loss before income taxes	(145,288)	(292,722)
Income tax expense	2,262	1,183
Net loss	$ (147,550)	$ (293,905)
Net loss per share:
Basic (in usd per share)	$ (1.05)	$ (3.41)
Diluted (in usd per share)	$ (1.05)	$ (3.41)
​Weighted average number of common shares outstanding:
Basic (in shares)	139,916	86,158
Diluted (in shares)	139,916	86,158
Product sales
Revenue:
Revenues	$ 82,324	$ (7,457)
Grants
Revenue:
Revenues	0	87,379
Royalties and other
Revenue:
Revenues	$ 11,531	$ 1,029

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (147,550)	$ (293,905)
Other comprehensive loss:
Foreign currency translation adjustment	(13,547)	3,211
Other comprehensive income (loss)	(13,547)	3,211
Comprehensive loss	$ (161,097)	$ (290,694)

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 480,586	$ 568,505
Restricted cash	10,455	10,424
Accounts receivable	21,380	297,240
Inventory	15,778	41,696
Prepaid expenses and other current assets	198,921	226,023
Total current assets	727,120	1,143,888
Property and equipment, net	291,093	305,771
Right of use asset, net	181,175	185,218
Goodwill	123,179	127,454
Other non-current assets	30,967	35,159
Total assets	1,353,534	1,797,490
Current liabilities:
Accounts payable	57,724	132,610
Accrued expenses	257,365	394,668
Deferred revenue	240,900	241,310
Current portion of finance lease liabilities	6,291	5,142
Other current liabilities	242,102	861,408
Total current liabilities	804,382	1,635,138
Deferred revenue	841,473	622,210
Convertible notes payable	168,432	168,016
Non-current finance lease liabilities	54,609	55,923
Other non-current liabilities	351,722	33,130
Total liabilities	2,220,618	2,514,417
Commitments and contingencies (Note 13)
Preferred stock, $0.01 par value, 2,000,000 shares authorized at March 31, 2024 and December 31, 2023; no shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Stockholders' deficit:
Common stock, $0.01 par value, 600,000,000 shares authorized at March 31, 2024 and December 31, 2023; 141,700,972 shares issued and 140,373,255 shares outstanding at March 31, 2024 and 140,506,093 shares issued and 139,505,770 shares outstanding at December 31, 2023	1,417	1,405
Additional paid-in capital	4,204,775	4,192,164
Accumulated deficit	(4,968,501)	(4,820,951)
Treasury stock, cost basis, 1,327,717 shares at March 31, 2024 and 1,000,323 shares at December 31, 2023	(93,950)	(92,267)
Accumulated other comprehensive income (loss)	(10,825)	2,722
Total stockholders’ deficit	(867,084)	(716,927)
Total liabilities and stockholders’ deficit	$ 1,353,534	$ 1,797,490

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par 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)	141,700,972	140,506,093
Common stock, shares outstanding (in shares)	140,373,255	139,505,770
Treasury stock (in shares)	1,327,717	1,000,323

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' 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, 2022		86,806,554
Balance beginning at Dec. 31, 2022	$ (634,078)	$ 868	$ 3,737,979	$ (4,275,889)	$ (90,659)	$ (6,377)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	28,647		28,647
Stock issued under incentive programs (in shares)		333,277
Stock issued under incentive programs	543	$ 3	1,107		(567)
Foreign currency translation adjustment	3,211					3,211
Net loss	(293,905)			(293,905)
Balance ending (in shares) at Mar. 31, 2023		87,139,831
Balance ending at Mar. 31, 2023	$ (895,582)	$ 871	3,767,733	(4,569,794)	(91,226)	(3,166)
Balance beginning (in shares) at Dec. 31, 2023	139,505,770	140,506,093
Balance beginning at Dec. 31, 2023	$ (716,927)	$ 1,405	4,192,164	(4,820,951)	(92,267)	2,722
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	11,556		11,556
Stock issued under incentive programs (in shares)		1,194,879
Stock issued under incentive programs	(616)	$ 12	1,055		(1,683)
Foreign currency translation adjustment	(13,547)					(13,547)
Net loss	$ (147,550)			(147,550)
Balance ending (in shares) at Mar. 31, 2024	140,373,255	141,700,972
Balance ending at Mar. 31, 2024	$ (867,084)	$ 1,417	$ 4,204,775	$ (4,968,501)	$ (93,950)	$ (10,825)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating Activities:
Net loss	$ (147,550)	$ (293,905)
Reconciliation of net loss to net cash used in operating activities:
Depreciation and amortization	12,147	9,043
Non-cash stock-based compensation	11,556	28,647
Provision for excess and obsolete inventory	8,807	12,490
Impairment of long-lived assets	1,669	0
Other items, net	(4,449)	(1,252)
Changes in operating assets and liabilities:
Inventory	16,819	(9,222)
Accounts receivable, prepaid expenses, and other assets	296,054	18,430
Accounts payable, accrued expenses, and other liabilities	(272,461)	(230,099)
Deferred revenue	(6,147)	140,275
Net cash used in operating activities	(83,555)	(325,593)
Investing Activities:
Capital expenditures	(6,878)	(19,801)
Internal-use software	(372)	(3,757)
Net cash used in investing activities	(7,250)	(23,558)
Financing Activities:
Net proceeds from sales of common stock	6,862	0
Net proceeds from the exercise of stock-based awards	(616)	543
Finance lease payments	(360)	(26,331)
Repayment of 2023 Convertible notes	0	(325,000)
Payments of costs related to issuance of 2027 Convertible notes	0	(3,591)
Net cash provided by (used in) financing activities	5,886	(354,379)
Effect of exchange rate on cash, cash equivalents, and restricted cash	(2,955)	(8,372)
Net decrease in cash, cash equivalents, and restricted cash	(87,874)	(711,902)
Cash, cash equivalents, and restricted cash at beginning of period	583,810	1,348,845
Cash, cash equivalents, and restricted cash at end of period	495,936	636,943
Supplemental disclosure of non-cash activities:
Capital expenditures included in accounts payable and accrued expenses	1,208	10,847
Internal-use software included in accounts payable and accrued expenses	250	0
Supplemental disclosure of cash flow information:
Cash interest payments, net of amounts capitalized	1,206	6,566
Cash paid for income taxes, net of refunds	$ (71)	$ 0

Organization and Business

Organization and Business	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business	Organization and Business Novavax, Inc. (“Novavax,” and together with its wholly owned subsidiaries, the “Company”) is a biotechnology company that promotes improved health by discovering, developing, and commercializing innovative vaccines to prevent serious infectious diseases. Novavax offers a differentiated vaccine platform that combines a recombinant protein approach, innovative nanoparticle technology and patented Matrix-M™ adjuvant to enhance the immune response. Novavax currently has one commercial program, for vaccines to prevent COVID-19, which includes Nuvaxovid™ prototype COVID-19 vaccine ("NVX-CoV2373,” or “prototype vaccine”) and Nuvaxovid™ updated COVID-19 vaccine (“NVX-CoV2601,” or “updated vaccine”) (collectively, “COVID-19 Vaccine”). Local regulatory authorities have also specified nomenclature for the labeling of the prototype and updated vaccines within their territories (e.g., “Novavax COVID-19 Vaccine, Adjuvanted” and “Novavax COVID-19, Adjuvanted (2023-2024 Formula),” respectively, for the U.S.). The Company’s partner, Serum Institute of India Pvt. Ltd. (“SIIPL”), markets NVX-CoV2373 as “Covovax™.” Beginning in 2022, the Company received approval, interim authorization, provisional approval, conditional marketing authorization, and emergency use authorization (“EUA”) from multiple regulatory authorities globally for its prototype vaccine for both adult and adolescent populations as a primary series and for both homologous and heterologous booster indications in select territories. In October 2023, the U.S. Food and Drug Administration amended the EUA for its prototype vaccine to include its updated vaccine. The amended EUA authorizes use of the Company’s updated vaccine in individuals 12 years and older. In October 2023, the European Commission (“EC”) granted approval for the Company’s updated vaccine for active immunization to prevent COVID-19 caused by SARS-CoV-2 in individuals aged 12 and older. Currently, the Company significantly depends on its supply agreement with SIIPL and its subsidiary, Serum Life Sciences Limited (“SLS”), for co-formulation, filling and finishing (other than in Europe) and on its service agreement with PCI Pharma Services for finishing in Europe. Novavax is advancing development of other vaccine candidates, including its COVID-19-Influenza Combination (“CIC”) vaccine candidate and additional vaccine candidates. The Company’s COVID-19 Vaccine and its other vaccine candidates incorporate the Company’s proprietary Matrix-M™ adjuvant to enhance the immune response and stimulate higher levels of functional antibodies and induce a cellular immune response.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. The consolidated financial statements are unaudited but include all adjustments (consisting of normal recurring adjustments) that the Company considers necessary for a fair presentation of the financial position, operating results, comprehensive loss, changes in stockholders’ deficit, and cash flows for the periods presented. Although the Company believes that the disclosures in these unaudited consolidated financial statements are adequate to make the information presented not misleading, certain information and footnote information normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted as permitted under the rules and regulations of the United States Securities and Exchange Commission (“SEC”). The unaudited consolidated financial statements include the accounts of Novavax, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The aggregate foreign currency transaction gains and losses resulting from the conversion of the transaction currency to functional currency were a $5.1 million loss and a $16.3 million gain for the three months ended March 31, 2024 and 2023, respectively, which are reflected in Other income (expense). The accompanying unaudited consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2023. Results for this or any interim period are not necessarily indicative of results for any future interim period or for the entire year. The Company operates in one business segment. Liquidity and Going Concern The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern within one year after the date that the financial statements are issued and contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainty described below. Management’s plans discussed below, including specifically the execution of the collaboration and license agreement (the “Collaboration and License Agreement”) and securities subscription agreement (the “Subscription Agreement”) effective May 10, 2024, with Sanofi Pasteur Inc. (“Sanofi”) which will result in cash proceeds to the Company of $568.8 million during the second quarter of 2024, has alleviated the substantial doubt outlined below regarding the Company’s ability to continue as a going concern for the one year period from the date that these financial statements were issued. As of March 31, 2024, the Company had $480.6 million in cash and cash equivalents and had a working capital deficiency. During the three months ended March 31, 2024, the Company incurred a net loss of $147.6 million and had net cash flows used in operating activities of $83.6 million. In accordance with Accounting Standards Codification (“ASC”) Topic 205-40, Presentation of Financial Statements - Going Concern, the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that these consolidated financial statements are issued. While the Company’s current cash flow forecast for the one-year going concern look forward period estimates that there will be sufficient capital available to fund operations, this forecast is subject to significant uncertainty, including as it relates to revenue for the next 12 months and the Company’s ability to execute on certain cost-reduction initiatives. The Company’s revenue projections depend on its ability to successfully develop, manufacture, distribute, and market its updated vaccine for the 2024-2025 vaccination season, which is inherently uncertain and subject to a number of risks, including the Company’s ability to obtain regulatory authorizations, introduce a single-dose vial or pre-filled syringe product presentation for the U.S. commercial and certain other markets, the incidence of COVID-19 during the 2024-2025 vaccination season, and the Company’s ability to timely deliver doses and achieve commercial adoption and market acceptance of its updated vaccine. Further, the Company’s revenue projections also depend on its ability to achieve expected product sales and related cash flows under its advance purchase agreements (“APAs”), including APAs in Australia and Canada, which are subject to regulatory uncertainties as described in Note 3. Failure to meet regulatory milestones or achieve product volume or delivery timing obligations under the Company’s APAs may require the Company to refund portions of upfront and other payments or result in reduced future payments, which would adversely affect the Company’s ability to continue as a going concern. Management believes that, given the history of recurring losses, negative working capital, and accumulated deficit, conditions or events exist that raise substantial doubt about the Company’s ability to continue as a going concern through one year from the date that these financial statements are issued. Management’s plans to potentially alleviate such conditions or events include the execution effective May 10, 2024, of the Collaboration and License Agreement with Sanofi that grants a co-exclusive license to Sanofi of the Company’s current COVID-19 and related vaccine products, which will provide the Company with an initial $500 million nonrefundable upfront payment, as well as the execution effective May 10, 2024, of the Subscription Agreement with Sanofi, which will provide the Company with a $68.8 million equity investment, both of which are expected to be received in the second quarter of 2024 and are described further below. Management’s plans also include execution of its commercial plans and its ongoing restructuring and cost reduction measures. On May 10, 2024, the Company entered into the Collaboration and License Agreement with Sanofi pursuant to which Sanofi received: i) A co-exclusive license to commercialize with the Company all of the Company’s current stand-alone COVID-19 vaccine products, including the Company’s Nuvaxovid™ prototype COVID-19 vaccine and Nuvaxovid™ updated COVID-19 vaccine, and updated versions that address seasonal variants throughout the world (“COVID Mono Products”), ii) A sole license to develop and commercialize combination products containing a potential combination of the Company’s COVID-19 vaccine and Sanofi’s seasonal influenza vaccine (“COVID and influenza Combination Products” or “CIC Products”), iii) A non-exclusive license to develop and commercialize combination products containing both the Company’s COVID-19 vaccine and one or more non-influenza vaccines (“Other Combination Products” and together with the COVID Mono Products, CIC Products, and Other Combination Products (“Licensed COVID-19 Products” )), and iv) A non-exclusive license to develop and commercialize other vaccine products selected by Sanofi that include the Company’s Matrix-M™ adjuvant (as described below, the “Adjuvant Products”). Under the Collaboration and License Agreement, the Company will receive a non-refundable upfront payment of $500 million. In addition, the Company will also be eligible to receive development, technology transfer, launch, and sales milestone payments totaling up to $700 million in the aggregate with respect to the Licensed COVID-19 Products and royalty payments on Sanofi’s sales of such licensed products. In addition, the Company is eligible to receive development, launch, and sales milestone payments of up to $200 million for each of the first four Adjuvant Products and $210 million for each Adjuvant Product thereafter, and royalty payments on Sanofi’s sales of all such licensed products. Commencing shortly after the Effective Date of the Collaboration and License Agreement, the Company will perform a technology transfer of its manufacturing process for the COVID Mono Products and Matrix-M™ components to Sanofi. Until the successful completion of such transfer, the Company will supply Sanofi with both COVID Mono Products and Matrix-M™ intermediary components for Sanofi’s use and is eligible for reimbursement of such costs from Sanofi. Additionally, Sanofi will reimburse the Company for its research and development and medical affairs costs related to the COVID Mono Products in accordance with agreed upon plans and budgets. Under the Collaboration and License Agreement, the Company will continue to commercialize the COVID Mono Products in 2024. Beginning in 2025 and continuing during the term of the Collaboration and License Agreement, Sanofi and the Company will commercialize the COVID Mono Products worldwide in accordance with a commercialization plan agreed by the Company and Sanofi, under which the Company will continue to supply its existing APA customers and strategic partners, including Takeda, SK Biosciences, and the Serum Institute of India. Upon completion of the existing advance purchase agreements, Novavax and Sanofi will jointly agree on commercialization activities of each party in each jurisdiction. Effective May 10, 2024, the Company also entered into the Subscription Agreement with Sanofi, pursuant to which the Company sold and issued to Sanofi, in a private placement, 6,880,481 shares of the Company’s common stock, par value $0.01 per share at a price of $10.00 per share for aggregate gross proceeds to the Company of $68.8 million. In May 2023, the Company announced a global restructuring and cost reduction plan (the “2023 Restructuring Plan”), which includes a more focused investment in its COVID-19 Vaccine, reduction to its pipeline spending, the continued rationalization of its manufacturing network, a reduction to the Company’s global workforce, as well as the consolidation of facilities, and infrastructure. In January 2024, as part of reducing combined research and development and selling, general and administrative expenses, the Company announced further reductions in its global workforce (the “2024 Cost Reduction Plan”). The Company intends to prioritize improvements to its long-term supply chain efficiency. The Company expects the full annual impact of the 2023 Restructuring Plan to be realized in 2024, the full annual impact of the 2024 Cost Reduction Plan to be realized in 2025, and approximately 85% of the annual impact of the 2024 Cost Reduction Plan, excluding one-time charges, to be realized in 2024. The 2024 Cost Reduction Plan supplemented the 2023 Restructuring Plan and hereafter both are jointly referred to as the “Restructuring Plan.” During the three months ended March 31, 2024, the Company recorded a charge of $4.4 million related to one-time employee severance and benefit costs and recorded an impairment charge of $1.7 million related to the impairment of capitalized internal-use software (see Note 14). Management’s plans may also include raising additional capital through a combination of additional equity and debt financing, additional collaborations, strategic alliances, asset sales, and marketing, distribution, or licensing arrangements. New financings may not be available to the Company on commercially acceptable terms, or at all. Also, any additional collaborations, strategic alliances, asset sales and marketing, distribution, or licensing arrangements may require the Company to give up some or all of its rights to a product or technology, which in some cases may be at less than the full potential value of such rights. If the Company is unable to obtain additional capital, the Company will assess its capital resources and may be required to delay, reduce the scope of, or eliminate some or all of its operations, or further downsize its organization, any of which may have a material adverse effect on its business, financial condition, results of operations, and ability to operate as a going concern. Management’s plans discussed above, including specifically the execution of the Collaboration and License Agreement and the Subscription Agreement effective May 10, 2024, with Sanofi which will result in cash proceeds to the Company of $568.8 million during the second quarter of 2024, has alleviated the substantial doubt outlined below regarding the Company’s ability to continue as a going concern for the one year period from the date that these financial statements were issued. Use of Estimates The preparation of the consolidated financial statements in conformity with 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. Restructuring The Company recognizes restructuring charges when such costs are incurred. The Company’s restructuring charges consist of employee severance and other termination benefits related to the reduction of its workforce, the consolidation of facilities, and infrastructure and other costs. Termination benefits are expensed on the date the Company notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period. Ongoing benefits are expensed when restructuring activities are probable and the benefit estimable. See Note 14 for additional information on the severance and employee benefit costs for terminated employees and impairment of assets in connection with the Company’s Restructuring Plan. Recent Accounting Pronouncements Not Yet Adopted In October 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-06, Disclosure Improvements (“ASU 2023-06”), to clarify or improve disclosure and presentation requirements of a variety of topics and align the requirements in the FASB ASC with the SEC's regulations. The Company is currently evaluating ASU 2023-06 to determine its impact on the Company's consolidated financial statements and disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures (“ASU 2023-09”). The standard enhances transparency in income tax disclosures by requiring, on an annual basis, certain disaggregated information about a reporting entity’s effective tax rate reconciliation and income taxes paid. The ASU also requires disaggregated disclosure related to pre-tax income (or loss) and income tax expense (or benefit) and eliminates certain disclosures related to the balance of an entity’s unrecognized tax benefit and the cumulative amount of certain temporary differences. The ASU is effective for the Company beginning on January 1, 2025. The Company is currently evaluating ASU 2023-09 to determine its impact on the Company's disclosures.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2024
Grants, U.S. Government Contract and Joint Venture [Abstract]
Revenue	Revenue The Company's accounts receivable included $21.2 million and $286.4 million related to amounts that were billed to customers and $0.2 million and $10.8 million related to amounts which had not yet been billed to customers as of March 31, 2024 and December 31, 2023, respectively. During the three months ended March 31, 2024 and 2023, changes in the Company’s accounts receivables, allowance for credit losses, and deferred revenue balances were as follows (in thousands): Balance, Beginning of Period Additions Deductions Balance, End of Period Accounts receivable: Three Months Ended March 31, 2024 $ 304,916 $ 136,510 $ (412,370) $ 29,056 Three Months Ended March 31, 2023 96,210 146,424 (115,950) 126,684 Allowance for credit losses (1) : Three Months Ended March 31, 2024 $ (7,676) $ — $ — $ (7,676) Three Months Ended March 31, 2023 (13,835) — — (13,835) Deferred revenue: (2) Three Months Ended March 31, 2024 $ 863,521 $ 225,000 $ (6,148) $ 1,082,373 Three Months Ended March 31, 2023 549,551 140,324 (49) 689,826 (1) There was no allowance for credit losses recorded during the three months ended March 31, 2024 or 2023. To estimate the allowance for credit losses, the Company evaluates the credit risk related to its customers based on historical loss experience, economic conditions, the aging of receivables, and customer-specific risks. (2) Deductions from Deferred revenue generally related to the recognition of revenue once performance obligations on a contract with a customer are met. During the three months ended March 31, 2024, deductions included a $2.2 million reclassification of refundable upfront payments previously included in Deferred revenue to Other current liabilities. During the three months ended March 31, 2024, additions included a $225.0 million reclassification of refundable upfront payment from Other current liabilities to Deferred revenue related to the settlement with Gavi as discussed below. There were no such reclassifications during the three months ended March 31, 2023. As of March 31, 2024, 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 $2 billion of which $1.1 billion was included in Deferred revenue. Failure to meet regulatory milestones, obtain timely supportive recommendations from governmental advisory committees, or achieve product volume or delivery timing obligations under the Company’s APAs may require the Company to refund portions of upfront and other payments or result in reduced future payments, which could adversely impact the Company’s ability to realize revenue from its unsatisfied performance obligations. The timing to fulfill performance obligations related to APAs will depend on the timing of product manufacturing, receipt of marketing authorizations for additional indications, delivery of doses based on customer demand, and the ability of the customer to request the Company’s updated vaccine under certain of the Company’s APAs. Under an APA with Gavi, the Vaccine Alliance (“Gavi”), entered into in May 2021 (the “Gavi APA”), the Company received upfront payments of $700 million from Gavi (the “Advance Payment Amount”) to be applied against purchases of the Company’s prototype vaccine by certain countries participating in the COVAX Facility. As of December 31, 2023, the remaining Gavi Advance Payment Amount was $696.4 million. On February 16, 2024, the Company entered into a Termination and Settlement Agreement with Gavi (the “Gavi Settlement Agreement”) terminating the Gavi APA, settling the arbitration proceedings, and releasing both parties of all claims arising from, under, or otherwise in connection with the Gavi APA. On February 22, 2024, the claims and counterclaims were dismissed with prejudice. Pursuant to the Gavi Settlement Agreement, the Company is responsible for payment to Gavi of (i) an initial settlement payment of $75 million, which the Company paid in February 2024, and (ii) deferred payments, in equal annual amounts of $80 million payable each calendar year through a deferred payment term ending December 31, 2028. The deferred payments are due in variable quarterly installments beginning in the second quarter of 2024 and total $400 million during the deferred payment term. Such deferred payments may be reduced through Gavi’s use of an annual vaccine credit equivalent to the unpaid balance of such deferred payments each year, which may be applied to qualifying sales of any of the Company’s vaccines for supply to certain low-income and lower-middle income countries. The Company has the right to price the vaccines offered to such low-income and lower-middle income countries in its discretion, and, when utilized by Gavi, the Company will credit the actual price per vaccine paid against the applicable credit. The Company intends to price vaccines offered via the tender process, consistent with its shared goal with Gavi to provide equitable access to those countries. Also, pursuant to the Gavi Settlement Agreement, the Company granted Gavi an additional credit of up to $225 million that may be applied against qualifying sales of any of the Company’s vaccines for supply to such low-income and lower-middle income countries that exceed the $80 million deferred payment amount in any calendar year during the deferred payment term. In total, the Gavi settlement agreement is comprised of $700 million of potential consideration, consisting of the $75 million initial settlement payment, deferred payments of up to $400 million that may be reduced through annual vaccine credits, and the additional credit of up to $225 million that may be applied for certain qualifying sales. The Company recorded the $3.6 million difference between the refund liability recorded as of December 31, 2023 of $696.4 million and the $700 million of total consideration under the arrangement as a reduction to revenue during the three months ended March 31, 2024. As of March 31, 2024, the remaining amounts included on the Company’s consolidated balance sheet are classified as $225 million in non-current Deferred revenue for the additional credit that may be applied against future qualifying sales, $80 million in Other current liabilities, and $320 million in Other non-current liabilities. In addition, the Company and Gavi entered into a security agreement pursuant to which Novavax granted Gavi a security interest in accounts receivable from SIIPL under the SIIPL R21 Agreement (see Note 4), which will continue for the deferred payment term of the Gavi Settlement Agreement. Product Sales Product sales by the Company’s customer’s geographic location was as follows (in thousands): Three Months Ended 2024 2023 North America $ (6,361) $ — Europe 90,416 57,267 Rest of the world (1,731) (64,724) Total product sales revenue $ 82,324 $ (7,457) Product sales in the U.S. are primarily made through large pharmaceutical wholesale distributors at the wholesale acquisition cost (“WAC”). Product sales in the U.S. are recorded net of gross-to-net deductions. During the three months ended March 31, 2024, product sales in North America includes $6.4 million of gross-to-net deductions in excess of the WAC, primarily due to wholesale distributor fees for shipments expected to be returned and adjustments made to estimated returns of prior period product sales. Product sales for the rest of the world includes a $3.6 million reduction to revenue recognized pursuant to the Gavi Settlement Agreement as discussed above. As of March 31, 2024, changes in the Company’s gross-to-net deductions balances were as follows (in thousands): Wholesale Distributor Fees, Discounts, and Chargebacks Product Returns Total Balance as of December 31, 2023 $ 21,072 $ 84,616 $ 105,688 Amounts charged against product sales (1) 16,076 19,296 35,372 Payments (26,979) (10,999) (37,978) Balance as of March 31, 2024 $ 10,169 $ 92,913 $ 103,082 (1) Amounts charged against product sales include $3.4 million of adjustments made to prior period product sales due primarily to changes in the estimate of product returns. As of March 31, 2024 and December 31, 2023, $5.4 million and $2.6 million of gross-to-net deductions were included in Accounts receivable, respectively, and $97.7 million and $103.1 million were included in Accrued expenses, respectively. The Company has an APA with the Commonwealth of Australia (“Australia”) for the purchase of doses of COVID-19 Vaccine (the “Australia APA”). In November 2023, the Company filed with the Therapeutic Goods Administration (“TGA”) for authorization for its updated vaccine. Based on subsequent communication from the TGA that it will not recommend approval of the filing as submitted and new data and information generated since that filing, the Company is evaluating the regulatory path for approval, including the potential to update the filing with new data and information, and resubmit in the coming months. In March 2024, the Company and Australia agreed to cancel the COVID-19 Vaccine doses previously scheduled for delivery in the fourth quarter of 2023. As a result of the cancellation, the total contract value was reduced by $54.0 million, including $6.0 million of deferred revenue related to the cancelled doses that will be applied as a credit towards future deliveries of doses. Under the Australia APA, Australia is not required to purchase the updated COVID-19 Vaccine doses until the Company receives authorization from TGA. The Company plans to seek an amendment to the Australia APA to address performance obligations and future delivery schedule, which may not be achievable on acceptable terms or at all. The Company had an APA with the EC acting on behalf of various European Union member states to supply a minimum of 20 million and up to 100 million initial doses of prototype vaccine, with the option for the EC to purchase an additional 100 million doses up to a maximum aggregate of 200 million doses in one or more tranches, through 2023. In January 2023, the Company finalized a revised delivery schedule for the remaining committed doses under the APA that were originally scheduled for delivery during the first and second quarters of 2022. The APA expired in August 2023 and required that any open and outstanding orders from European Union member states be satisfied by February 2024. All outstanding orders were delivered to European Union Member states by February 2024. The Company has an APA with His Majesty the King in Right of Canada as represented by the Minister of Public Works and Government Services, as successor in interest to Her Majesty the Queen in Right of Canada, as represented by the Minister of Public Works and Government Services (the “Canadian government”), for the purchase of doses of COVID-19 Vaccine (the “Canada APA”). The Canadian government may terminate the Canada APA, as amended, if the Company fails to receive regulatory approval for its COVID-19 Vaccine using bulk antigen produced at Biologics Manufacturing Centre (“BMC”) Inc. on or before December 31, 2024 . The Company does not anticipate achieving regulatory approval of its COVID-19 Vaccine using bulk antigen produced at BMC on or before December 31, 2024 . Therefore, the Company plans to seek an amendment to the Canada APA to address possible alternatives, which may not be achievable on acceptable terms or at all. As of March 31, 2024, $110.6 million was classified as current Deferred revenue and $477.6 million was classified as non-current Deferred revenue with respect to the Canadian APA in the Company’s consolidated balance sheet. If the Canadian government terminates the Canada APA, $28.0 million of the deferred revenue would become refundable and approximately $224 million of the contract value related to future deliverables would no longer be available. Grants The Company’s U.S. government agreement consisted of a Project Agreement (the “Project Agreement”) and a Base Agreement with Advanced Technology International, the Consortium Management Firm acting on behalf of the Medical CBRN Defense Consortium in connection with the partnership formerly known as Operation Warp Speed (the Base Agreement together with the Project Agreement the “USG Agreement”). As of December 31, 2023, the Company recognized the full $1.8 billion funding in revenue. Royalties and Other Royalties and other includes royalty milestone payments, sales-based royalties, and Matrix-M™ adjuvant sales. During the three months ended March 31, 2024, the Company recognized $4.0 million in revenue related to license fees and $7.5 million in revenue related to a Matrix-M™ adjuvant sales. During the three months ended March 31, 2024, the Company did not recognize revenue related to milestone payments. During the three months ended March 31, 2023, the Company recognized $1.0 million in revenue related to a Matrix-M™ adjuvant sales. During the three months ended March 31, 2023, the Company did not recognize revenue related to license fees or milestone payments. SIIPL The Company previously granted SIIPL exclusive and non-exclusive licenses for the development, co-formulation, filling and finishing, registration, and commercialization of its prototype vaccine, its proprietary COVID-19 variant antigen candidate(s), and its CIC vaccine candidate. SIIPL agreed to purchase the Company's Matrix-M™ adjuvant and the Company granted SIIPL a non-exclusive license to manufacture the antigen drug substance component of the Company’s COVID-19 Vaccine in SIIPL’s licensed territory solely for use in the manufacture of COVID-19 Vaccine. The Company and SIIPL equally split the revenue from SIIPL’s sale of COVID-19 Vaccine in its licensed territory, net of agreed costs. The Company also has a supply agreement with SIIPL and SLS under which SIIPL and SLS supply the Company with prototype vaccine, its proprietary COVID-19 variant antigen candidate(s), and its CIC vaccine candidate for commercialization and sale in certain territories, as well as a contract development manufacture agreement with SLS, under which SLS manufactures and supplies finished vaccine product to the Company using antigen drug substance and Matrix-M™ adjuvant supplied by the Company. In March 2020, the Company entered into an agreement with SIIPL that granted SIIPL a non-exclusive license for the use of Matrix-M™ adjuvant supplied by the Company to develop, manufacture, and commercialize R21/Matrix-M™ adjuvant (“SIIPL R21 Agreement”), a malaria vaccine created by the Jenner Institute, University of Oxford (“R21/Matrix-M™”). In December 2023, R21/Matrix-M™ received prequalification by the World Health Organization (“WHO”). Under the SIIPL R21 Agreement, SIIPL purchases the Company's Matrix-M™ adjuvant for use in development activities at cost and for commercial purposes at a tiered commercial supply price, and pays a royalty in the single-to low- double-digit range based on vaccine sales for a period of 15 years after the first commercial sale of the vaccine in each country. Takeda Pharmaceutical Company Limited The Company has 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 the Company’s COVID-19 Vaccine in Japan. Under the agreement, Takeda purchases Matrix-M™ adjuvant from the Company to manufacture doses of COVID-19 Vaccine, and the Company is entitled to receive milestone and sales-based royalty 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 COVID-19 Vaccine. 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 its prototype vaccine. In February 2023, MHLW canceled the remainder of doses under its agreement with Takeda. As a result, it is uncertain whether the Company will receive future sales-based royalty payments from Takeda under the terms and conditions of their current collaboration and licensing agreement. Sanofi Effective May 10, 2024, the Company entered into the Collaboration and License Agreement with Sanofi pursuant to which Sanofi received: i) A co-exclusive license to commercialize with the Company all of the COVID Mono Products, ii) A sole license to develop and commercialize combination COVID and influenza Combination Products, iii) A non-exclusive license to develop and commercialize Other Combination Products, and iv) A non-exclusive license to develop and commercialize Adjuvant Products. Under the Collaboration and License Agreement, the Company will receive a non-refundable upfront payment of $500 million. In addition, the Company will also be eligible to receive development, technology transfer, launch, and sales milestone payments totaling up to $700 million in the aggregate with respect to the Licensed COVID-19 Products and royalty payments on Sanofi’s sales of such licensed products. In addition, the Company is eligible to receive development, launch, and sales milestone payments of up to $200 million for each of the first four Adjuvant Products and $210 million for each Adjuvant Product thereafter, and royalty payments on Sanofi’s sales of all such licensed products. Commencing shortly after the Effective Date of the Collaboration and License Agreement, the Company will perform a technology transfer of its manufacturing process for the COVID Mono Products and Matrix-M™ components to Sanofi. Until the successful completion of such transfer, the Company will supply Sanofi with both COVID Mono Products and Matrix-M™ intermediary components for Sanofi’s use and is eligible for reimbursement of such costs from Sanofi. Additionally, Sanofi will reimburse the Company for its research and development and medical affairs costs related to the COVID Mono Products in accordance with agreed upon plans and budgets. Under the Collaboration and License Agreement, the Company will continue to commercialize the COVID Mono Products in 2024. Beginning in 2025 and continuing during the term of the Collaboration and License Agreement, Sanofi and the Company will commercialize the COVID Mono Products worldwide in accordance with a commercialization plan agreed by the Company and Sanofi, under which the Company will continue to supply its existing APA customers and strategic partners, including Takeda, SK Biosciences, and the Serum Institute of India. Upon completion of the existing advance purchase agreements, Novavax and Sanofi will jointly agree on commercialization activities of each party in each jurisdiction. Bill & Melinda Gates Medical Research Institute In May 2023, the Company entered into a three-year agreement with the Bill & Melinda Gates Medical Research Institute to provide the Company’s Matrix-M™ adjuvant for use in preclinical vaccine research. Other Supply Agreements In March 2024, the Company, FUJIFILM Diosynth Biotechnologies UK Limited (“FDBK”), FUJIFILM Diosynth Biotechnologies Texas, LLC (“FDBT”) and FUJIFILM Diosynth Biotechnologies USA, Inc. (“FDBU” and together with FDBK and FDBT, “Fujifilm”) entered into a Confidential Settlement Agreement and Release (the “Settlement Agreement”) to resolve disputes regarding amounts that Fujifilm claimed were due under a prior Confidential Settlement Agreement and Release effective September 30, 2022 (the “CSAR”) by and between the Company and Fujifilm. Under the CSAR, the Company agreed to pay up to $185.0 million to Fujifilm in connection with the cancellation of manufacturing activity at FDBT. The final two quarterly installments due to Fujifilm in 2023 under the CSAR, totaling $68.6 million, were subject to Fujifilm’s obligation to use commercially reasonable efforts to mitigate losses associated with the vacant manufacturing capacity caused by the termination of manufacturing activities at FDBT. In October 2023, the Company sent Fujifilm a notice of breach and refused to pay the final two installments based on its contention that Fujifilm had not used commercially reasonable efforts to mitigate losses and should have offset some portion of the final two payments. In October 2023, Fujifilm filed a demand for arbitration with Judicial Arbitration and Mediation Services (“JAMS”) seeking payment of the full amount (the “Fujifilm Arbitration”). Pursuant to the Settlement Agreement, in March 2024 the Company paid $42.0 million to Fujifilm, the parties agreed to a mutual release of claims arising from, under or otherwise in connection with the CSAR, and Fujifilm agreed to dismiss the Fujifilm Arbitration. This payment is less than amounts previously accrued for and reflected in Research and development expense, and accordingly, the Company recorded a benefit of $26.6 million as Research and development expense during the three months ended March 31, 2024 upon the execution of the Settlement Agreement. The Company continues to assess its manufacturing needs and intends to modify its global manufacturing footprint consistent with its contractual obligations to supply, and anticipated demand for, its COVID-19 Program, and in doing so, recognizes that significant costs may be incurred.

Collaboration, License, and Sup

Collaboration, License, and Supply Agreements	3 Months Ended
	Mar. 31, 2024
Collaborative Arrangement [Abstract]
Collaboration, License, and Supply Agreements	Revenue The Company's accounts receivable included $21.2 million and $286.4 million related to amounts that were billed to customers and $0.2 million and $10.8 million related to amounts which had not yet been billed to customers as of March 31, 2024 and December 31, 2023, respectively. During the three months ended March 31, 2024 and 2023, changes in the Company’s accounts receivables, allowance for credit losses, and deferred revenue balances were as follows (in thousands): Balance, Beginning of Period Additions Deductions Balance, End of Period Accounts receivable: Three Months Ended March 31, 2024 $ 304,916 $ 136,510 $ (412,370) $ 29,056 Three Months Ended March 31, 2023 96,210 146,424 (115,950) 126,684 Allowance for credit losses (1) : Three Months Ended March 31, 2024 $ (7,676) $ — $ — $ (7,676) Three Months Ended March 31, 2023 (13,835) — — (13,835) Deferred revenue: (2) Three Months Ended March 31, 2024 $ 863,521 $ 225,000 $ (6,148) $ 1,082,373 Three Months Ended March 31, 2023 549,551 140,324 (49) 689,826 (1) There was no allowance for credit losses recorded during the three months ended March 31, 2024 or 2023. To estimate the allowance for credit losses, the Company evaluates the credit risk related to its customers based on historical loss experience, economic conditions, the aging of receivables, and customer-specific risks. (2) Deductions from Deferred revenue generally related to the recognition of revenue once performance obligations on a contract with a customer are met. During the three months ended March 31, 2024, deductions included a $2.2 million reclassification of refundable upfront payments previously included in Deferred revenue to Other current liabilities. During the three months ended March 31, 2024, additions included a $225.0 million reclassification of refundable upfront payment from Other current liabilities to Deferred revenue related to the settlement with Gavi as discussed below. There were no such reclassifications during the three months ended March 31, 2023. As of March 31, 2024, 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 $2 billion of which $1.1 billion was included in Deferred revenue. Failure to meet regulatory milestones, obtain timely supportive recommendations from governmental advisory committees, or achieve product volume or delivery timing obligations under the Company’s APAs may require the Company to refund portions of upfront and other payments or result in reduced future payments, which could adversely impact the Company’s ability to realize revenue from its unsatisfied performance obligations. The timing to fulfill performance obligations related to APAs will depend on the timing of product manufacturing, receipt of marketing authorizations for additional indications, delivery of doses based on customer demand, and the ability of the customer to request the Company’s updated vaccine under certain of the Company’s APAs. Under an APA with Gavi, the Vaccine Alliance (“Gavi”), entered into in May 2021 (the “Gavi APA”), the Company received upfront payments of $700 million from Gavi (the “Advance Payment Amount”) to be applied against purchases of the Company’s prototype vaccine by certain countries participating in the COVAX Facility. As of December 31, 2023, the remaining Gavi Advance Payment Amount was $696.4 million. On February 16, 2024, the Company entered into a Termination and Settlement Agreement with Gavi (the “Gavi Settlement Agreement”) terminating the Gavi APA, settling the arbitration proceedings, and releasing both parties of all claims arising from, under, or otherwise in connection with the Gavi APA. On February 22, 2024, the claims and counterclaims were dismissed with prejudice. Pursuant to the Gavi Settlement Agreement, the Company is responsible for payment to Gavi of (i) an initial settlement payment of $75 million, which the Company paid in February 2024, and (ii) deferred payments, in equal annual amounts of $80 million payable each calendar year through a deferred payment term ending December 31, 2028. The deferred payments are due in variable quarterly installments beginning in the second quarter of 2024 and total $400 million during the deferred payment term. Such deferred payments may be reduced through Gavi’s use of an annual vaccine credit equivalent to the unpaid balance of such deferred payments each year, which may be applied to qualifying sales of any of the Company’s vaccines for supply to certain low-income and lower-middle income countries. The Company has the right to price the vaccines offered to such low-income and lower-middle income countries in its discretion, and, when utilized by Gavi, the Company will credit the actual price per vaccine paid against the applicable credit. The Company intends to price vaccines offered via the tender process, consistent with its shared goal with Gavi to provide equitable access to those countries. Also, pursuant to the Gavi Settlement Agreement, the Company granted Gavi an additional credit of up to $225 million that may be applied against qualifying sales of any of the Company’s vaccines for supply to such low-income and lower-middle income countries that exceed the $80 million deferred payment amount in any calendar year during the deferred payment term. In total, the Gavi settlement agreement is comprised of $700 million of potential consideration, consisting of the $75 million initial settlement payment, deferred payments of up to $400 million that may be reduced through annual vaccine credits, and the additional credit of up to $225 million that may be applied for certain qualifying sales. The Company recorded the $3.6 million difference between the refund liability recorded as of December 31, 2023 of $696.4 million and the $700 million of total consideration under the arrangement as a reduction to revenue during the three months ended March 31, 2024. As of March 31, 2024, the remaining amounts included on the Company’s consolidated balance sheet are classified as $225 million in non-current Deferred revenue for the additional credit that may be applied against future qualifying sales, $80 million in Other current liabilities, and $320 million in Other non-current liabilities. In addition, the Company and Gavi entered into a security agreement pursuant to which Novavax granted Gavi a security interest in accounts receivable from SIIPL under the SIIPL R21 Agreement (see Note 4), which will continue for the deferred payment term of the Gavi Settlement Agreement. Product Sales Product sales by the Company’s customer’s geographic location was as follows (in thousands): Three Months Ended 2024 2023 North America $ (6,361) $ — Europe 90,416 57,267 Rest of the world (1,731) (64,724) Total product sales revenue $ 82,324 $ (7,457) Product sales in the U.S. are primarily made through large pharmaceutical wholesale distributors at the wholesale acquisition cost (“WAC”). Product sales in the U.S. are recorded net of gross-to-net deductions. During the three months ended March 31, 2024, product sales in North America includes $6.4 million of gross-to-net deductions in excess of the WAC, primarily due to wholesale distributor fees for shipments expected to be returned and adjustments made to estimated returns of prior period product sales. Product sales for the rest of the world includes a $3.6 million reduction to revenue recognized pursuant to the Gavi Settlement Agreement as discussed above. As of March 31, 2024, changes in the Company’s gross-to-net deductions balances were as follows (in thousands): Wholesale Distributor Fees, Discounts, and Chargebacks Product Returns Total Balance as of December 31, 2023 $ 21,072 $ 84,616 $ 105,688 Amounts charged against product sales (1) 16,076 19,296 35,372 Payments (26,979) (10,999) (37,978) Balance as of March 31, 2024 $ 10,169 $ 92,913 $ 103,082 (1) Amounts charged against product sales include $3.4 million of adjustments made to prior period product sales due primarily to changes in the estimate of product returns. As of March 31, 2024 and December 31, 2023, $5.4 million and $2.6 million of gross-to-net deductions were included in Accounts receivable, respectively, and $97.7 million and $103.1 million were included in Accrued expenses, respectively. The Company has an APA with the Commonwealth of Australia (“Australia”) for the purchase of doses of COVID-19 Vaccine (the “Australia APA”). In November 2023, the Company filed with the Therapeutic Goods Administration (“TGA”) for authorization for its updated vaccine. Based on subsequent communication from the TGA that it will not recommend approval of the filing as submitted and new data and information generated since that filing, the Company is evaluating the regulatory path for approval, including the potential to update the filing with new data and information, and resubmit in the coming months. In March 2024, the Company and Australia agreed to cancel the COVID-19 Vaccine doses previously scheduled for delivery in the fourth quarter of 2023. As a result of the cancellation, the total contract value was reduced by $54.0 million, including $6.0 million of deferred revenue related to the cancelled doses that will be applied as a credit towards future deliveries of doses. Under the Australia APA, Australia is not required to purchase the updated COVID-19 Vaccine doses until the Company receives authorization from TGA. The Company plans to seek an amendment to the Australia APA to address performance obligations and future delivery schedule, which may not be achievable on acceptable terms or at all. The Company had an APA with the EC acting on behalf of various European Union member states to supply a minimum of 20 million and up to 100 million initial doses of prototype vaccine, with the option for the EC to purchase an additional 100 million doses up to a maximum aggregate of 200 million doses in one or more tranches, through 2023. In January 2023, the Company finalized a revised delivery schedule for the remaining committed doses under the APA that were originally scheduled for delivery during the first and second quarters of 2022. The APA expired in August 2023 and required that any open and outstanding orders from European Union member states be satisfied by February 2024. All outstanding orders were delivered to European Union Member states by February 2024. The Company has an APA with His Majesty the King in Right of Canada as represented by the Minister of Public Works and Government Services, as successor in interest to Her Majesty the Queen in Right of Canada, as represented by the Minister of Public Works and Government Services (the “Canadian government”), for the purchase of doses of COVID-19 Vaccine (the “Canada APA”). The Canadian government may terminate the Canada APA, as amended, if the Company fails to receive regulatory approval for its COVID-19 Vaccine using bulk antigen produced at Biologics Manufacturing Centre (“BMC”) Inc. on or before December 31, 2024 . The Company does not anticipate achieving regulatory approval of its COVID-19 Vaccine using bulk antigen produced at BMC on or before December 31, 2024 . Therefore, the Company plans to seek an amendment to the Canada APA to address possible alternatives, which may not be achievable on acceptable terms or at all. As of March 31, 2024, $110.6 million was classified as current Deferred revenue and $477.6 million was classified as non-current Deferred revenue with respect to the Canadian APA in the Company’s consolidated balance sheet. If the Canadian government terminates the Canada APA, $28.0 million of the deferred revenue would become refundable and approximately $224 million of the contract value related to future deliverables would no longer be available. Grants The Company’s U.S. government agreement consisted of a Project Agreement (the “Project Agreement”) and a Base Agreement with Advanced Technology International, the Consortium Management Firm acting on behalf of the Medical CBRN Defense Consortium in connection with the partnership formerly known as Operation Warp Speed (the Base Agreement together with the Project Agreement the “USG Agreement”). As of December 31, 2023, the Company recognized the full $1.8 billion funding in revenue. Royalties and Other Royalties and other includes royalty milestone payments, sales-based royalties, and Matrix-M™ adjuvant sales. During the three months ended March 31, 2024, the Company recognized $4.0 million in revenue related to license fees and $7.5 million in revenue related to a Matrix-M™ adjuvant sales. During the three months ended March 31, 2024, the Company did not recognize revenue related to milestone payments. During the three months ended March 31, 2023, the Company recognized $1.0 million in revenue related to a Matrix-M™ adjuvant sales. During the three months ended March 31, 2023, the Company did not recognize revenue related to license fees or milestone payments. SIIPL The Company previously granted SIIPL exclusive and non-exclusive licenses for the development, co-formulation, filling and finishing, registration, and commercialization of its prototype vaccine, its proprietary COVID-19 variant antigen candidate(s), and its CIC vaccine candidate. SIIPL agreed to purchase the Company's Matrix-M™ adjuvant and the Company granted SIIPL a non-exclusive license to manufacture the antigen drug substance component of the Company’s COVID-19 Vaccine in SIIPL’s licensed territory solely for use in the manufacture of COVID-19 Vaccine. The Company and SIIPL equally split the revenue from SIIPL’s sale of COVID-19 Vaccine in its licensed territory, net of agreed costs. The Company also has a supply agreement with SIIPL and SLS under which SIIPL and SLS supply the Company with prototype vaccine, its proprietary COVID-19 variant antigen candidate(s), and its CIC vaccine candidate for commercialization and sale in certain territories, as well as a contract development manufacture agreement with SLS, under which SLS manufactures and supplies finished vaccine product to the Company using antigen drug substance and Matrix-M™ adjuvant supplied by the Company. In March 2020, the Company entered into an agreement with SIIPL that granted SIIPL a non-exclusive license for the use of Matrix-M™ adjuvant supplied by the Company to develop, manufacture, and commercialize R21/Matrix-M™ adjuvant (“SIIPL R21 Agreement”), a malaria vaccine created by the Jenner Institute, University of Oxford (“R21/Matrix-M™”). In December 2023, R21/Matrix-M™ received prequalification by the World Health Organization (“WHO”). Under the SIIPL R21 Agreement, SIIPL purchases the Company's Matrix-M™ adjuvant for use in development activities at cost and for commercial purposes at a tiered commercial supply price, and pays a royalty in the single-to low- double-digit range based on vaccine sales for a period of 15 years after the first commercial sale of the vaccine in each country. Takeda Pharmaceutical Company Limited The Company has 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 the Company’s COVID-19 Vaccine in Japan. Under the agreement, Takeda purchases Matrix-M™ adjuvant from the Company to manufacture doses of COVID-19 Vaccine, and the Company is entitled to receive milestone and sales-based royalty 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 COVID-19 Vaccine. 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 its prototype vaccine. In February 2023, MHLW canceled the remainder of doses under its agreement with Takeda. As a result, it is uncertain whether the Company will receive future sales-based royalty payments from Takeda under the terms and conditions of their current collaboration and licensing agreement. Sanofi Effective May 10, 2024, the Company entered into the Collaboration and License Agreement with Sanofi pursuant to which Sanofi received: i) A co-exclusive license to commercialize with the Company all of the COVID Mono Products, ii) A sole license to develop and commercialize combination COVID and influenza Combination Products, iii) A non-exclusive license to develop and commercialize Other Combination Products, and iv) A non-exclusive license to develop and commercialize Adjuvant Products. Under the Collaboration and License Agreement, the Company will receive a non-refundable upfront payment of $500 million. In addition, the Company will also be eligible to receive development, technology transfer, launch, and sales milestone payments totaling up to $700 million in the aggregate with respect to the Licensed COVID-19 Products and royalty payments on Sanofi’s sales of such licensed products. In addition, the Company is eligible to receive development, launch, and sales milestone payments of up to $200 million for each of the first four Adjuvant Products and $210 million for each Adjuvant Product thereafter, and royalty payments on Sanofi’s sales of all such licensed products. Commencing shortly after the Effective Date of the Collaboration and License Agreement, the Company will perform a technology transfer of its manufacturing process for the COVID Mono Products and Matrix-M™ components to Sanofi. Until the successful completion of such transfer, the Company will supply Sanofi with both COVID Mono Products and Matrix-M™ intermediary components for Sanofi’s use and is eligible for reimbursement of such costs from Sanofi. Additionally, Sanofi will reimburse the Company for its research and development and medical affairs costs related to the COVID Mono Products in accordance with agreed upon plans and budgets. Under the Collaboration and License Agreement, the Company will continue to commercialize the COVID Mono Products in 2024. Beginning in 2025 and continuing during the term of the Collaboration and License Agreement, Sanofi and the Company will commercialize the COVID Mono Products worldwide in accordance with a commercialization plan agreed by the Company and Sanofi, under which the Company will continue to supply its existing APA customers and strategic partners, including Takeda, SK Biosciences, and the Serum Institute of India. Upon completion of the existing advance purchase agreements, Novavax and Sanofi will jointly agree on commercialization activities of each party in each jurisdiction. Bill & Melinda Gates Medical Research Institute In May 2023, the Company entered into a three-year agreement with the Bill & Melinda Gates Medical Research Institute to provide the Company’s Matrix-M™ adjuvant for use in preclinical vaccine research. Other Supply Agreements In March 2024, the Company, FUJIFILM Diosynth Biotechnologies UK Limited (“FDBK”), FUJIFILM Diosynth Biotechnologies Texas, LLC (“FDBT”) and FUJIFILM Diosynth Biotechnologies USA, Inc. (“FDBU” and together with FDBK and FDBT, “Fujifilm”) entered into a Confidential Settlement Agreement and Release (the “Settlement Agreement”) to resolve disputes regarding amounts that Fujifilm claimed were due under a prior Confidential Settlement Agreement and Release effective September 30, 2022 (the “CSAR”) by and between the Company and Fujifilm. Under the CSAR, the Company agreed to pay up to $185.0 million to Fujifilm in connection with the cancellation of manufacturing activity at FDBT. The final two quarterly installments due to Fujifilm in 2023 under the CSAR, totaling $68.6 million, were subject to Fujifilm’s obligation to use commercially reasonable efforts to mitigate losses associated with the vacant manufacturing capacity caused by the termination of manufacturing activities at FDBT. In October 2023, the Company sent Fujifilm a notice of breach and refused to pay the final two installments based on its contention that Fujifilm had not used commercially reasonable efforts to mitigate losses and should have offset some portion of the final two payments. In October 2023, Fujifilm filed a demand for arbitration with Judicial Arbitration and Mediation Services (“JAMS”) seeking payment of the full amount (the “Fujifilm Arbitration”). Pursuant to the Settlement Agreement, in March 2024 the Company paid $42.0 million to Fujifilm, the parties agreed to a mutual release of claims arising from, under or otherwise in connection with the CSAR, and Fujifilm agreed to dismiss the Fujifilm Arbitration. This payment is less than amounts previously accrued for and reflected in Research and development expense, and accordingly, the Company recorded a benefit of $26.6 million as Research and development expense during the three months ended March 31, 2024 upon the execution of the Settlement Agreement. The Company continues to assess its manufacturing needs and intends to modify its global manufacturing footprint consistent with its contractual obligations to supply, and anticipated demand for, its COVID-19 Program, and in doing so, recognizes that significant costs may be incurred.

Cash, Cash Equivalents, and Res

Cash, Cash Equivalents, and Restricted Cash	3 Months Ended
	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Restricted Cash	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 sums to the total of such amounts shown in the consolidated statements of cash flows (in thousands): March 31, 2024 December 31, 2023 Cash and cash equivalents $ 480,586 $ 568,505 Restricted cash, current 10,455 10,424 Restricted cash, non-current (1) 4,895 4,881 Cash, cash equivalents, and restricted cash $ 495,936 $ 583,810 (1) Classified as Other non-current assets as of March 31, 2024 and December 31, 2023, on the consolidated balance sheets.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following table represents the Company’s fair value hierarchy for its financial assets and liabilities (in thousands): Fair Value at March 31, 2024 Fair Value at December 31, 2023 Assets Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Money market funds (1) $ 118,470 $ — $ — $ 171,824 $ — $ — Government-backed securities (1) — 200,000 — — 200,000 — Treasury securities (1) — 46,875 — — 45,622 — Corporate debt securities (1) — 61,428 — — — — Total cash equivalents $ 118,470 $ 308,303 $ — $ 171,824 $ 245,622 $ — Liabilities 5.00% Convertible notes due 2027 $ — $ 109,088 $ — $ — $ 100,909 $ — (1) All investments are classified as Cash and cash equivalents as of March 31, 2024 and December 31, 2023, 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 convertible notes has been estimated using observable inputs, including the price of the Company’s common stock, implied volatility, interest rates, and credit spreads. During the three months ended March 31, 2024 and 2023, 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.

Inventory

Inventory	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consisted of the following (in thousands): March 31, 2024 December 31, 2023 Raw materials $ 5,295 $ 6,614 Semi-finished goods 8,984 7,392 Finished goods 1,499 27,690 Total inventory $ 15,778 $ 41,696 Inventory write-downs as a result of excess, obsolescence, expiry, or other reasons, and losses on firm purchase commitments, offset by recoveries of such commitments, are recorded as a component of cost of sales in the Company’s consolidated statements of operations. For the three months ended March 31, 2024, inventory write-downs were $8.8 million. For the three months ended March 31, 2023, inventory write-downs were $12.5 million and losses on firm purchase commitments were $7.7 million. In addition, for the three months ended March 31, 2023 the Company recorded recoveries on

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The Company has one reporting unit, which has a negative carrying amount as of March 31, 2024 and December 31, 2023. The change in the carrying amounts of goodwill for the three months ended March 31, 2024 was as follows (in thousands): Amount Balance at December 31, 2023 $ 127,454 Currency translation adjustments (4,275) Balance at March 31, 2024 $ 123,179

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Total convertible notes payable consisted of the following (in thousands): March 31, 2024 December 31, 2023 5.00% Convertible notes due 2027 $ 175,250 $ 175,250 Unamortized debt issuance costs (6,818) (7,234) Total convertible notes payable $ 168,432 $ 168,016 The effective interest rate of the 2027 Convertible notes is 6.2%. During the three months ended March 31, 2023, the Company repaid the outstanding principal amount of $325.0 million on its 3.75% Convertible notes due in 2023, together with accrued but unpaid interest on the maturity date. The interest expense incurred in connection with the convertible notes payable consisted of the following (in thousands): Three Months Ended 2024 2023 Coupon interest $ 2,192 $ 3,206 Amortization of debt issuance costs 416 510 Total interest expense on convertible notes payable $ 2,608 $ 3,716

Stockholders' Deficit

Stockholders' Deficit	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Deficit	Stockholders’ Deficit In August 2023, the Company entered into an At Market Issuance Sales Agreement (the “August 2023 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 then-existing At Market Issuance Sales agreement entered in June 2021 (the “June 2021 Sales Agreement”). During the three months ended March 31, 2024, there were no sales recorded under the August 2023 Sales Agreement. As of March 31, 2024, the remaining balance available under the August 2023 Sales Agreement was approximately $242 million. During the three months ended March 31, 2023, there were no sales recorded under the June 2021 Sales Agreement.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Equity Plans In January 2023, the Company established the 2023 Inducement Plan (the “2023 Inducement Plan”), which provides for the granting of share-based awards to individuals who were not previously employees, or following a bona fide period of non-employment, as an inducement material to such individuals entering into employment with the Company. The Company reserved 1.0 million shares of common stock for grants under the 2023 Inducement Plan. As of March 31, 2024, there were 0.2 million shares available for issuance under the 2023 Inducement Plan. 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 21.0 million shares of common stock under equity awards granted under the 2015 Plan. All such shares authorized for issuance under the 2015 Plan have been reserved. The 2015 Plan will expire on March 30, 2033. As of March 31, 2024, there were 2.6 million shares available for issuance under the 2015 Plan. 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 2023 Inducement Plan and the 2015 Plan permit, and the 2005 Plan permitted, the grant of stock options (including incentive stock options), restricted stock, stock appreciation rights (“SARs”), and restricted stock units (“RSUs”). In addition, under the 2023 Inducement Plan and the 2015 Plan, unrestricted stock, stock units, and performance awards may be granted. Stock options and SARs generally have a maximum term of ten 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 share-based awards 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): Three Months Ended 2024 2023 Cost of sales $ 594 $ 519 Research and development 5,505 13,858 Selling, general, and administrative 5,457 14,270 Total stock-based compensation expense $ 11,556 $ 28,647 During the three months ended March 31, 2024, and March 31, 2023, there was no stock-based compensation capitalized in inventory. As of March 31, 2024, there was approximately $87 million of total unrecognized compensation expense related to unvested stock options, SARs, RSUs, and the ESPP. This unrecognized non-cash compensation expense is expected to be recognized over a weighted-average period of approximately two years and will be allocated between cost of sales, 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. 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 SARs) that would have been received by the holders had all stock option and SAR holders exercised their stock options and SARs on March 31, 2024. 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 SARs exercises and vesting of RSUs for the three months ended March 31, 2024 and 2023 was approximately $4.5 million and $1.5 million, respectively. Stock Options and Stock Appreciation Rights The following is a summary of stock options and SARs activity under the 2023 Inducement Plan, 2015 Plan, and 2005 Plan for the three months ended March 31, 2024: 2023 Inducement Plan 2015 Plan 2005 Plan Stock Weighted-Average Stock Weighted-Average Stock Weighted-Average Outstanding at December 31, 2023 422,800 $ 10.67 4,787,042 $ 38.10 58,275 $ 119.79 Granted — — 594,367 5.39 — — Exercised — — (142) 5.22 — — Canceled — — (284,823) 37.60 (57,569) 120.01 Outstanding at March 31, 2024 422,800 $ 10.67 5,096,444 $ 34.31 706 $ 102.11 Shares exercisable at March 31, 2024 101,762 $ 11.08 3,411,898 $ 41.21 706 $ 102.11 The fair value of stock options granted under the 2023 Inducement Plan and the 2015 Plan was estimated at the date of grant using the Black-Scholes option-pricing model with the following assumptions: Three Months Ended 2024 2023 Weighted average Black-Scholes fair value of stock options granted $4.34 $7.19 Risk-free interest rate 4.3% 3.6%-4.0% Dividend yield —% —% Volatility 114.3%-121.1% 127.7%-140.3% Expected term (in years) 3.9-4.4 3.9-5.1 The total aggregate intrinsic value and weighted-average remaining contractual term of stock options and SARs outstanding under the 2023 Inducement Plan, 2015 Plan and 2005 Plan as of March 31, 2024 was less than $0.1 million and 7.1 years, respectively. The total aggregate intrinsic value and weighted-average remaining contractual term of stock options and SARs exercisable under the 2023 Inducement Plan, 2015 Plan and 2005 Plan as of March 31, 2024 was less than $0.1 million and 6.0 years, respectively. Restricted Stock Units The following is a summary of RSU activity for the three months ended March 31, 2024: 2023 Inducement Plan 2015 Plan Number of Per Share Number of Per Share Outstanding and unvested at December 31, 2023 363,990 $ 10.66 3,714,870 $ 19.43 Granted — — 4,358,623 5.38 Vested (102,797) 10.96 (778,278) 23.96 Forfeited — — (359,910) 20.66 Outstanding and unvested at March 31, 2024 261,193 $ 10.55 6,935,305 $ 10.03 Employee Stock Purchase Plan The ESPP was approved at the Company’s annual meeting of stockholders in June 2013. The ESPP currently authorized an aggregate of 1.2 million shares of common stock to be purchased, and the aggregate number of shares will continue to increase 5% on each anniversary of its adoption up to a maximum of 1.6 million shares. 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). As of March 31, 2024, there were 0.2 million shares available for issuance under the ESPP.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company evaluates the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. Significant pieces of objective evidence evaluated by the Company were the cumulative loss incurred over the three-year period ended March 31, 2024 and that the Company has historically generated pretax losses. Such objective evidence limits the ability to consider other subjective evidence, such as projections for future growth. On the basis of this evaluation, as of March 31, 2024, the Company continued to maintain a full valuation allowance against its deferred tax assets, except to the extent Net Operating Losses (“NOLs”) have been used to reduce taxable income. As of March 31, 2024, the Company has $2.4 billion of U.S. Federal NOLs carryforward, and all but $11.3 million are subject to limitation in accordance with the 2017 Tax Cuts and Jobs Act (“TCJA”), which limits allowable NOL deductions to 80% of federal taxable income.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Matters Stockholder Litigation On November 12, 2021, Sothinathan Sinnathurai filed a purported securities class action in the U.S. District Court for the District of Maryland (the “Maryland Court”) against the Company and certain members of senior management, captioned Sothinathan Sinnathurai v. Novavax, Inc., et al., No. 8:21-cv-02910-TDC (the “Sinnathurai Action”). On January 26, 2022, the Maryland Court entered an order designating David Truong, Nuggehalli Balmukund Nandkumar, and Jeffrey Gabbert as co-lead plaintiffs in the Sinnathurai Action. The co-lead plaintiffs filed a consolidated amended complaint on March 11, 2022, alleging that the defendants made certain purportedly false and misleading statements concerning the Company’s ability to manufacture prototype vaccine on a commercial scale and to secure the prototype vaccine’s regulatory approval. The amended complaint defines the purported class as those stockholders who purchased the Company’s securities between February 24, 2021 and October 19, 2021. On April 25, 2022, the defendants filed a motion to dismiss the consolidated amended complaint. On December 12, 2022, the Maryland Court issued a ruling granting in part and denying in part defendants’ motion to dismiss. The Maryland Court dismissed all claims against two individual defendants and claims based on certain public statements challenged in the consolidated amended complaint. The Maryland Court denied the motion to dismiss as to the remaining claims and defendants, and directed the Company and other remaining defendants to answer within fourteen days. On December 27, 2022, the Company filed its answer and affirmative defenses. On March 16, 2023, the plaintiffs filed a motion for class certification and to appoint class representatives and counsel. The Company filed its opposition to the plaintiffs’ motion on September 22, 2023. On December 4, 2023, the parties agreed to a binding settlement in principle (the “Proposed Settlement”) to fully resolve the surviving claims in the Sinnathurai Action. Under the Proposed Settlement’s terms, the Company agreed to pay $47 million into a settlement fund, which will be funded by the Company’s directors and officers’ liability insurance and paid to members of a putative settlement class. On January 12, 2024, after the parties negotiated and executed a written agreement governing the Proposed Settlement, plaintiffs filed an unopposed motion for the Proposed Settlement’s preliminary approval. On January 23, 2024, the Maryland Court granted the motion for preliminary approval and, as requested by the parties, preliminarily certified, for the purposes of settlement only, the settlement class. The court also scheduled a settlement hearing to consider final approval of the settlement for May 23, 2024. Ahead of the May 23 settlement hearing, on April 11, 2024, Plaintiffs filed a motion seeking the Maryland Court’s final approval of the settlement. The Company determined that the settlement is probable and the insurance funding is realizable and, as such, recorded the $47 million estimated settlement liability within Accrued expenses and the $47 million estimated insurance recovery within Prepaid expenses and other current assets on the consolidated balance sheet as of December 31, 2023 and March 31, 2024. After the Sinnathurai Action was filed, eight derivative lawsuits were filed: (i) Robert E. Meyer v. Stanley C. Erck, et al., No. 8:21-cv-02996-TDC (the “Meyer Action”), (ii) Shui Shing Yung v. Stanley C. Erck, et al., No. 8:21-cv-03248-TDC (the “Yung Action”), (iii) William Kirst, et al. v. Stanley C. Erck, et al., No. C-15-CV-21-000618 (the “Kirst Action”), (iv) Amy Snyder v. Stanley C. Erck, et al., No. 8:22-cv-01415-TDC (the “Snyder Action”), (v) Charles R. Blackburn, et al. v. Stanley C. Erck, et al., No. 1:22-cv-01417-TDC (the “Blackburn Action”), (vi) Diego J. Mesa v. Stanley C. Erck, et al., No. 2022-0770-NAC (the “Mesa Action”), (vii) Sean Acosta v. Stanley C. Erck, et al., No. 2022-1133-NAC (the “Acosta Action”), and (viii) Jared Needelman v. Stanley C. Erck, et al., No. C-15-CV-23-001550 (the “Needelman Action”). The Meyer, Yung, Snyder, and Blackburn Actions were filed in the Maryland Court. The Kirst Action was filed in the Circuit Court for Montgomery County, Maryland, and shortly thereafter removed to the Maryland Court by the defendants. The Needleman Action was also filed in the Circuit Court for Montgomery County, Maryland. The Mesa and Acosta Actions were filed in the Delaware Court of Chancery (the “Delaware Court”). The derivative lawsuits name members of the Company’s board of directors and certain members of senior management as defendants. The Company is deemed a nominal defendant. The 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. On February 7, 2022, the Maryland Court entered an order consolidating the Meyer and Yung Actions (the “First Consolidated Derivative Action”). The plaintiffs in the First Consolidated Derivative Action filed their consolidated derivative complaint on April 25, 2022. On May 10, 2022, the Maryland Court entered an order granting the parties’ request to stay all proceedings and deadlines pending the earlier of dismissal or the filing of an answer in the Sinnathurai Action. On June 10, 2022, the Snyder and Blackburn Actions were filed. On October 5, 2022, the Maryland Court entered an order granting a request by the plaintiffs in the First Consolidated Derivative Action and the Snyder and Blackburn Actions to consolidate all three actions and appoint co-lead plaintiffs and co-lead and liaison counsel (the “Second Consolidated Derivative Action”). The co-lead plaintiffs in the Second Consolidated Derivative Action filed a consolidated amended complaint on November 21, 2022. On February 10, 2023, defendants filed a motion to dismiss the Second Consolidated Derivative Action. The plaintiffs filed their opposition to the motion to dismiss on April 11, 2023. Defendants filed their reply brief in further support of their motion to dismiss on May 11, 2023. On August 21, 2023, the court entered an order granting in part and denying in part the motion to dismiss. On September 5, 2023, the Company filed an Answer to the consolidated amended complaint. On September 6, 2023, the court entered an order granting the individual defendants an extension of time to file their answer until November 6, 2023. On October 6, 2023, the Board of Directors of the Company formed a Special Litigation Committee (“SLC”) with full and exclusive power and authority of the Board to, among other things, investigate, review, and analyze the facts and circumstances surrounding the claims asserted in the pending derivative actions, including the claims that remain following the court’s order on the motion to dismiss in the Second Consolidated Derivative Action. On November 7, 2023, the court entered an order granting the parties’ request to stay the Second Consolidated Derivative Action for up to six months from the date of entry of the order, and, on April 15, 2024, the court entered a further order extending the stay by an additional month, and, on April 15, 2024, the court entered a further order extending the stay by an additional month. This includes staying the deadline for the individual defendants to respond to the consolidated amended complaint. The Kirst Action was filed on December 28, 2021, and the defendants immediately removed the case to the Maryland Court. On July 21, 2022, the Maryland Court issued a memorandum opinion and order remanding the Kirst Action to state court. The plaintiffs filed an amended complaint on December 30, 2022. On January 23, 2023, defendants filed a motion to stay the Kirst action. On February 22, 2023, the parties in the Kirst Action filed for the Court’s approval of a stipulation staying the Kirst Action pending the resolution of defendants’ motion to dismiss in the Second Consolidated Derivative Action. On March 22, 2023, the Court entered the parties’ stipulated stay of the Kirst Action pending resolution of the motion to dismiss in the Second Consolidated Derivative Action. On August 30, 2022, the Mesa Action was filed. On October 3, 2022, the Delaware Court entered an order granting the parties’ request to stay all proceedings and deadlines in the Mesa Action pending the earlier of dismissal of the Sinnathurai Action or the filing of an answer to the operative complaint in the Sinnathurai Action. On January 9, 2023, following the ruling on the motion to dismiss the Sinnathurai Action, the Delaware Court entered an order granting the Mesa Action parties’ request to set a briefing schedule in connection with a motion to stay by defendants. On February 28, 2023, the court granted the defendants’ motion and stayed the Mesa Action pending the entry of a final, non-appealable judgment in the Second Consolidated Derivative Action. On August 31, 2023, the Mesa plaintiffs filed a motion to lift the stay in the Mesa Action. On October 6, 2023, the Company filed an opposition to plaintiff’s motion to lift the stay. Plaintiff filed his reply on October 17, 2023. On December 27, 2023, the parties filed a letter informing the Court that the Second Consolidated Derivative Action had been stayed for a period of six months and asked the Court to stay further proceedings in the Mesa Action until expiration of that stay. On December 7, 2022, the Acosta Action was filed. On February 6, 2023, defendants accepted service of the complaint and summons in the Acosta Action. On March 9, 2023, the court entered an order granting the parties’ request to stay the Acosta Action pending the entry of a final, non-appealable judgment in the Second Consolidated Derivative Action. On October 13, 2023, the parties filed, and the Delaware Court entered, a stipulated order providing that (i) if the Delaware Court declines to lift the stay in the Mesa Action, the Acosta Action will also remain stayed, and (ii) if the Delaware Court lifts the stay in the Mesa Action, the stay in the Acosta Action will also be lifted. On April 17, 2023, the Needelman Action was filed. On July 12, 2023, the parties filed a stipulation and proposed order to stay the Needelman Action pending the Maryland Court’s decision on the motion to dismiss in the Second Consolidated Derivative Action. The court entered that order on July 17, 2023. On November 30, 2023, the court entered an order consolidating the Kirst and Needelman Actions. On December 14, 2023, the parties filed a stipulation (i) extending the plaintiffs’ deadline to file a consolidated complaint until January 29, 2024, and (ii) otherwise staying all other proceedings in the case (including the defendants’ deadline to respond to the consolidated complaint) until February 12, 2024. The stipulation entered by the court instructs the parties to discuss whether the stay should be further extended in light of the then-current status of the SLC’s investigation. On May 3, 2024, the plaintiffs filed a consolidated complaint. The parties are discussing whether to extend defendants' deadline to respond to the consolidated complaint through early June. The financial impact of the above derivative claims is not estimable. On November 18, 2022, the Company delivered written notice to Gavi to terminate the Gavi APA based on Gavi’s failure to procure the purchase of 350 million doses of prototype vaccine from the Company as required by the Gavi APA. As of November 18, 2022, the Company had only received orders under the Gavi APA for approximately 2 million doses. On December 2, 2022, Gavi issued a written notice purporting to terminate the Gavi APA based on Gavi’s contention that the Company repudiated the agreement and, therefore, materially breached the Gavi APA. Gavi also contended that, based on its purported termination of the Gavi APA, it was entitled to a refund of the Advance Payment Amount less any amounts that have been credited against the purchase price for binding orders placed by a buyer participating in the COVAX Facility. Since December 31, 2022, the remaining Gavi Advance Payment Amount, which was $696.4 million as of December 31, 2023, pending resolution of the dispute with Gavi related to a return of the remaining Advance Payment Amount, has been classified within Other current liabilities in the Company’s consolidated balance sheet. On January 24, 2023, Gavi filed a demand for arbitration with the International Court of Arbitration based on the claims described above. The Company filed its Answer and Counterclaims on March 2, 2023. On April 5, 2023, Gavi filed its Reply to the Company’s Counterclaims. On February 16, 2024, the Company entered into a Termination and Settlement Agreement with Gavi (the “Gavi Settlement Agreement”) terminating the Gavi APA, settling the arbitration proceedings, and releasing both parties of all claims arising from, under, or otherwise in connection with the Gavi APA. Pursuant to the Gavi Settlement Agreement, the Company is responsible for payment to Gavi of (i) an initial settlement payment of $75 million, which the Company paid in February 2024, and (ii) deferred payments, in equal annual amounts of $80 million payable each calendar year through a deferred payment term ending December 31, 2028. The deferred payments are due in variable quarterly installments beginning in the second quarter of 2024 and total $400 million during the deferred payment term. Such deferred payments may be reduced through Gavi’s use of an annual vaccine credit equivalent to the unpaid balance of such deferred payments each year, which may be applied to qualifying sales of any of the Company’s vaccines for supply to certain low-income and lower-middle income countries. The Company has the right to price the vaccines offered to such low-income and lower-middle income countries in its discretion, and, when utilized by Gavi, the Company will credit the actual price per vaccine paid against the applicable credit. The Company intends to price vaccines offered via the tender process, consistent with its shared goal with Gavi to provide equitable access to those countries. Also, pursuant to the Gavi Settlement Agreement, the Company granted Gavi an additional credit of up to $225 million that may be applied against qualifying sales of any of the Company’s vaccines for supply to such low-income and lower-middle income countries that exceed the $80 million deferred payment amount in any calendar year during the deferred payment term. In total, the Gavi settlement agreement is comprised of $700 million of potential consideration, consisting of the $75 million initial settlement payment, deferred payments of up to $400 million that may be reduced through annual vaccine credits, and the additional credit of up to $225 million that may be applied for certain qualifying sales. In addition, the Company and Gavi entered into a security agreement pursuant to which Novavax granted Gavi a security interest in accounts receivable from SIIPL under the SIIPL R21 Agreement (see Note 4), which will continue for the deferred payment term of the Gavi Settlement Agreement. On February 22, 2024, the claims and counterclaims were dismissed with prejudice. On September 30, 2022, the Company and Fujifilm entered into the CSAR regarding amounts due to Fujifilm in connection with the termination of manufacturing activity at FDBT under the Commercial Supply Agreement dated August 20, 2021 (the “CSA”) and the Master Services Agreement dated June 30, 2020 and associated statements of work (the “MSA”) by and between the Company and Fujifilm. The MSA and CSA established the general terms and conditions applicable to Fujifilm’s manufacturing and supply activities related to the Company’s prototype vaccine under the associated statements of work. Pursuant to the CSAR, the Company agreed to pay up to $185.0 million (the “Settlement Payment”) to Fujifilm in connection with cancellation of manufacturing activity at FDBT. Under the CSAR, the final two quarterly installments due to Fujifilm were subject to Fujifilm’s obligation to use commercially reasonable efforts to mitigate losses associated with the vacant manufacturing capacity caused by the termination of manufacturing activities at FDBT under the CSA. Any replacement revenue achieved by Fujifilm’s mitigation efforts between July 1, 2023 and December 31, 2023 would offset the final two settlement payments owed by the Company. On October 2, 2023, the Company sent a notice of breach under the Fujifilm Settlement Agreement to Fujifilm setting forth the Company’s position that Fujifilm had not used commercially reasonable efforts to mitigate losses. The Company withheld the $34.3 million installment payment due to Fujifilm on September 30, 2023, pending resolution of the issues identified in the notice of breach (see Note 4). On October 30, 2023, FDBT filed a demand for arbitration with JAMS seeking payment of the third quarter installment of the Settlement Payment. An arbitration hearing was scheduled for May 2024. As of December 31, 2023, the remaining payment of $68.6 million was reflected in Accrued expenses. On March 21, 2024, the Company and Fujifilm entered into a Settlement Agreement to resolve disputes regarding amounts that Fujifilm claimed were due under the CSAR. Pursuant to the Settlement Agreement, in March 2024 the Company paid $42.0 million to Fujifilm, the parties agreed to a mutual release of claims arising from, under or otherwise in connection with the CSAR, and Fujifilm agreed to dismiss the Fujifilm Arbitration. This payment is less than amounts previously accrued for and reflected in Research and development expense, and accordingly, the Company recorded a benefit of $26.6 million as Research and development expense in the first quarter of 2024 upon the execution of the Settlement Agreement. The Company is also involved in various other legal proceedings arising in the normal course of business. Although the outcomes of these other legal proceedings are inherently difficult to predict, the Company does not expect the resolution of these other legal proceedings to have a material adverse effect on its financial position, results of operations, or cash flows.

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring During the three months ended March 31, 2024, the restructuring charge recorded by the Company comprised (in thousands): Amount Severance and employee benefit costs $ 4,401 Impairment of assets 1,669 Total Restructuring charge (1) $ 6,070 (1) Restructuring charges of $1.6 million and $4.5 million are included in Research and development and Selling, general, and administrative expenses, respectively, in the Consolidated Statements of Operations for the three months ended March 31, 2024. During the three months ended March 31, 2023, the Company did not recognize any restructuring charges. Severance and employee benefit costs Employees affected by the reduction in force under the Restructuring Plan are entitled to receive severance payments and certain termination benefits. The Company recorded a severance and termination benefit cost in full for employees who were notified of their termination in the three months ended March 31, 2024 and had no requirements for future service. The Company paid a total of $3.9 million for the severance and employee benefit costs during the three months ended March 31, 2024 and the remaining liability of $0.5 million is included in Accrued expenses in the Company’s consolidated balance sheet as of March 31, 2024. Impairment of assets In connection with the Restructuring Plan, the Company evaluated its long-lived assets for impairment including certain leased laboratory and office spaces located in Gaithersburg, Maryland. The Company performed an impairment evaluation for the applicable long-lived assets, which is subject to judgment and actual results may vary from the estimates, resulting in potential future adjustments to amounts recorded. During the three months ended March 31, 2024, the Company recorded an impairment charge of $1.7 million related to the impairment of capitalized internal-use software.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Effective May 10, 2024, the Company entered into the Collaboration and License Agreement with Sanofi pursuant to which Sanofi received: i) A co-exclusive license to commercialize with the Company all of the COVID Mono Products, ii) A sole license to develop and commercialize combination COVID and influenza Combination Products, iii) A non-exclusive license to develop and commercialize Other Combination Products, and iv) A non-exclusive license to develop and commercialize Adjuvant Products. Under the Collaboration and License Agreement, the Company will receive a non-refundable upfront payment of $500 million. In addition, the Company will also be eligible to receive development, technology transfer, launch, and sales milestone payments totaling up to $700 million in the aggregate with respect to the Licensed COVID-19 Products and royalty payments on Sanofi’s sales of such licensed products. In addition, the Company is eligible to receive development, launch, and sales milestone payments of up to $200 million for each of the first four Adjuvant Products and $210 million for each Adjuvant Product thereafter, and royalty payments on Sanofi’s sales of all such licensed products. Commencing shortly after the Effective Date of the Collaboration and License Agreement, the Company will perform a technology transfer of its manufacturing process for the COVID Mono Products and Matrix-M™ components to Sanofi. Until the successful completion of such transfer, the Company will supply Sanofi with both COVID Mono Products and Matrix-M™ intermediary components for Sanofi’s use and is eligible for reimbursement of such costs from Sanofi. Additionally, Sanofi will reimburse the Company for its research and development and medical affairs costs related to the COVID Mono Products in accordance with agreed upon plans and budgets. Under the Collaboration and License Agreement, the Company will continue to commercialize the COVID Mono Products in 2024. Beginning in 2025 and continuing during the term of the Collaboration and License Agreement, Sanofi and the Company will commercialize the COVID Mono Products worldwide in accordance with a commercialization plan agreed by the Company and Sanofi, under which the Company will continue to supply its existing APA customers and strategic partners, including Takeda, SK Biosciences, and the Serum Institute of India. Upon completion of the existing advance purchase agreements, Novavax and Sanofi will jointly agree on commercialization activities of each party in each jurisdiction.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net loss	$ (147,550)	$ (293,905)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. The consolidated financial statements are unaudited but include all adjustments (consisting of normal recurring adjustments) that the Company considers necessary for a fair presentation of the financial position, operating results, comprehensive loss, changes in stockholders’ deficit, and cash flows for the periods presented. Although the Company believes that the disclosures in these unaudited consolidated financial statements are adequate to make the information presented not misleading, certain information and footnote information normally included in consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted as permitted under the rules and regulations of the United States Securities and Exchange Commission (“SEC”). The unaudited consolidated financial statements include the accounts of Novavax, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The aggregate foreign currency transaction gains and losses resulting from the conversion of the transaction currency to functional currency were a $5.1 million loss and a $16.3 million gain for the three months ended March 31, 2024 and 2023, respectively, which are reflected in Other income (expense). The accompanying unaudited consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2023. Results for this or any interim period are not necessarily indicative of results for any future interim period or for the entire year. The Company operates in one business segment.
Liquidity and Going Concern	Liquidity and Going Concern The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern within one year after the date that the financial statements are issued and contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainty described below. Management’s plans discussed below, including specifically the execution of the collaboration and license agreement (the “Collaboration and License Agreement”) and securities subscription agreement (the “Subscription Agreement”) effective May 10, 2024, with Sanofi Pasteur Inc. (“Sanofi”) which will result in cash proceeds to the Company of $568.8 million during the second quarter of 2024, has alleviated the substantial doubt outlined below regarding the Company’s ability to continue as a going concern for the one year period from the date that these financial statements were issued. As of March 31, 2024, the Company had $480.6 million in cash and cash equivalents and had a working capital deficiency. During the three months ended March 31, 2024, the Company incurred a net loss of $147.6 million and had net cash flows used in operating activities of $83.6 million. In accordance with Accounting Standards Codification (“ASC”) Topic 205-40, Presentation of Financial Statements - Going Concern, the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that these consolidated financial statements are issued. While the Company’s current cash flow forecast for the one-year going concern look forward period estimates that there will be sufficient capital available to fund operations, this forecast is subject to significant uncertainty, including as it relates to revenue for the next 12 months and the Company’s ability to execute on certain cost-reduction initiatives. The Company’s revenue projections depend on its ability to successfully develop, manufacture, distribute, and market its updated vaccine for the 2024-2025 vaccination season, which is inherently uncertain and subject to a number of risks, including the Company’s ability to obtain regulatory authorizations, introduce a single-dose vial or pre-filled syringe product presentation for the U.S. commercial and certain other markets, the incidence of COVID-19 during the 2024-2025 vaccination season, and the Company’s ability to timely deliver doses and achieve commercial adoption and market acceptance of its updated vaccine. Further, the Company’s revenue projections also depend on its ability to achieve expected product sales and related cash flows under its advance purchase agreements (“APAs”), including APAs in Australia and Canada, which are subject to regulatory uncertainties as described in Note 3. Failure to meet regulatory milestones or achieve product volume or delivery timing obligations under the Company’s APAs may require the Company to refund portions of upfront and other payments or result in reduced future payments, which would adversely affect the Company’s ability to continue as a going concern. Management believes that, given the history of recurring losses, negative working capital, and accumulated deficit, conditions or events exist that raise substantial doubt about the Company’s ability to continue as a going concern through one year from the date that these financial statements are issued. Management’s plans to potentially alleviate such conditions or events include the execution effective May 10, 2024, of the Collaboration and License Agreement with Sanofi that grants a co-exclusive license to Sanofi of the Company’s current COVID-19 and related vaccine products, which will provide the Company with an initial $500 million nonrefundable upfront payment, as well as the execution effective May 10, 2024, of the Subscription Agreement with Sanofi, which will provide the Company with a $68.8 million equity investment, both of which are expected to be received in the second quarter of 2024 and are described further below. Management’s plans also include execution of its commercial plans and its ongoing restructuring and cost reduction measures. On May 10, 2024, the Company entered into the Collaboration and License Agreement with Sanofi pursuant to which Sanofi received: i) A co-exclusive license to commercialize with the Company all of the Company’s current stand-alone COVID-19 vaccine products, including the Company’s Nuvaxovid™ prototype COVID-19 vaccine and Nuvaxovid™ updated COVID-19 vaccine, and updated versions that address seasonal variants throughout the world (“COVID Mono Products”), ii) A sole license to develop and commercialize combination products containing a potential combination of the Company’s COVID-19 vaccine and Sanofi’s seasonal influenza vaccine (“COVID and influenza Combination Products” or “CIC Products”), iii) A non-exclusive license to develop and commercialize combination products containing both the Company’s COVID-19 vaccine and one or more non-influenza vaccines (“Other Combination Products” and together with the COVID Mono Products, CIC Products, and Other Combination Products (“Licensed COVID-19 Products” )), and iv) A non-exclusive license to develop and commercialize other vaccine products selected by Sanofi that include the Company’s Matrix-M™ adjuvant (as described below, the “Adjuvant Products”). Under the Collaboration and License Agreement, the Company will receive a non-refundable upfront payment of $500 million. In addition, the Company will also be eligible to receive development, technology transfer, launch, and sales milestone payments totaling up to $700 million in the aggregate with respect to the Licensed COVID-19 Products and royalty payments on Sanofi’s sales of such licensed products. In addition, the Company is eligible to receive development, launch, and sales milestone payments of up to $200 million for each of the first four Adjuvant Products and $210 million for each Adjuvant Product thereafter, and royalty payments on Sanofi’s sales of all such licensed products. Commencing shortly after the Effective Date of the Collaboration and License Agreement, the Company will perform a technology transfer of its manufacturing process for the COVID Mono Products and Matrix-M™ components to Sanofi. Until the successful completion of such transfer, the Company will supply Sanofi with both COVID Mono Products and Matrix-M™ intermediary components for Sanofi’s use and is eligible for reimbursement of such costs from Sanofi. Additionally, Sanofi will reimburse the Company for its research and development and medical affairs costs related to the COVID Mono Products in accordance with agreed upon plans and budgets. Under the Collaboration and License Agreement, the Company will continue to commercialize the COVID Mono Products in 2024. Beginning in 2025 and continuing during the term of the Collaboration and License Agreement, Sanofi and the Company will commercialize the COVID Mono Products worldwide in accordance with a commercialization plan agreed by the Company and Sanofi, under which the Company will continue to supply its existing APA customers and strategic partners, including Takeda, SK Biosciences, and the Serum Institute of India. Upon completion of the existing advance purchase agreements, Novavax and Sanofi will jointly agree on commercialization activities of each party in each jurisdiction. Effective May 10, 2024, the Company also entered into the Subscription Agreement with Sanofi, pursuant to which the Company sold and issued to Sanofi, in a private placement, 6,880,481 shares of the Company’s common stock, par value $0.01 per share at a price of $10.00 per share for aggregate gross proceeds to the Company of $68.8 million. In May 2023, the Company announced a global restructuring and cost reduction plan (the “2023 Restructuring Plan”), which includes a more focused investment in its COVID-19 Vaccine, reduction to its pipeline spending, the continued rationalization of its manufacturing network, a reduction to the Company’s global workforce, as well as the consolidation of facilities, and infrastructure. In January 2024, as part of reducing combined research and development and selling, general and administrative expenses, the Company announced further reductions in its global workforce (the “2024 Cost Reduction Plan”). The Company intends to prioritize improvements to its long-term supply chain efficiency. The Company expects the full annual impact of the 2023 Restructuring Plan to be realized in 2024, the full annual impact of the 2024 Cost Reduction Plan to be realized in 2025, and approximately 85% of the annual impact of the 2024 Cost Reduction Plan, excluding one-time charges, to be realized in 2024. The 2024 Cost Reduction Plan supplemented the 2023 Restructuring Plan and hereafter both are jointly referred to as the “Restructuring Plan.” During the three months ended March 31, 2024, the Company recorded a charge of $4.4 million related to one-time employee severance and benefit costs and recorded an impairment charge of $1.7 million related to the impairment of capitalized internal-use software (see Note 14). Management’s plans may also include raising additional capital through a combination of additional equity and debt financing, additional collaborations, strategic alliances, asset sales, and marketing, distribution, or licensing arrangements. New financings may not be available to the Company on commercially acceptable terms, or at all. Also, any additional collaborations, strategic alliances, asset sales and marketing, distribution, or licensing arrangements may require the Company to give up some or all of its rights to a product or technology, which in some cases may be at less than the full potential value of such rights. If the Company is unable to obtain additional capital, the Company will assess its capital resources and may be required to delay, reduce the scope of, or eliminate some or all of its operations, or further downsize its organization, any of which may have a material adverse effect on its business, financial condition, results of operations, and ability to operate as a going concern. Management’s plans discussed above, including specifically the execution of the Collaboration and License Agreement and the Subscription Agreement effective May 10, 2024, with Sanofi which will result in cash proceeds to the Company of $568.8 million during the second quarter of 2024, has alleviated the substantial doubt outlined below regarding the Company’s ability to continue as a going concern for the one year period from the date that these financial statements were issued.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with 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.
Restructuring	Restructuring The Company recognizes restructuring charges when such costs are incurred. The Company’s restructuring charges consist of employee severance and other termination benefits related to the reduction of its workforce, the consolidation of facilities, and infrastructure and other costs. Termination benefits are expensed on the date the Company notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period. Ongoing benefits are expensed when restructuring activities are probable and the benefit estimable. See Note 14 for additional information on the severance and employee benefit costs for terminated employees and impairment of assets in connection with the Company’s Restructuring Plan.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Not Yet Adopted In October 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-06, Disclosure Improvements (“ASU 2023-06”), to clarify or improve disclosure and presentation requirements of a variety of topics and align the requirements in the FASB ASC with the SEC's regulations. The Company is currently evaluating ASU 2023-06 to determine its impact on the Company's consolidated financial statements and disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures (“ASU 2023-09”). The standard enhances transparency in income tax disclosures by requiring, on an annual basis, certain disaggregated information about a reporting entity’s effective tax rate reconciliation and income taxes paid. The ASU also requires disaggregated disclosure related to pre-tax income (or loss) and income tax expense (or benefit) and eliminates certain disclosures related to the balance of an entity’s unrecognized tax benefit and the cumulative amount of certain temporary differences. The ASU is effective for the Company beginning on January 1, 2025. The Company is currently evaluating ASU 2023-09 to determine its impact on the Company's disclosures.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2024
Grants, U.S. Government Contract and Joint Venture [Abstract]
Schedule of Accounts Receivable, Unbilled Services, and Deferred Revenue	During the three months ended March 31, 2024 and 2023, changes in the Company’s accounts receivables, allowance for credit losses, and deferred revenue balances were as follows (in thousands): Balance, Beginning of Period Additions Deductions Balance, End of Period Accounts receivable: Three Months Ended March 31, 2024 $ 304,916 $ 136,510 $ (412,370) $ 29,056 Three Months Ended March 31, 2023 96,210 146,424 (115,950) 126,684 Allowance for credit losses (1) : Three Months Ended March 31, 2024 $ (7,676) $ — $ — $ (7,676) Three Months Ended March 31, 2023 (13,835) — — (13,835) Deferred revenue: (2) Three Months Ended March 31, 2024 $ 863,521 $ 225,000 $ (6,148) $ 1,082,373 Three Months Ended March 31, 2023 549,551 140,324 (49) 689,826 (1) There was no allowance for credit losses recorded during the three months ended March 31, 2024 or 2023. To estimate the allowance for credit losses, the Company evaluates the credit risk related to its customers based on historical loss experience, economic conditions, the aging of receivables, and customer-specific risks.
Schedule of Product Revenue	Product sales by the Company’s customer’s geographic location was as follows (in thousands): Three Months Ended 2024 2023 North America $ (6,361) $ — Europe 90,416 57,267 Rest of the world (1,731) (64,724) Total product sales revenue $ 82,324 $ (7,457)
Schedule of Revenue Gross to Net Deductions Balances	As of March 31, 2024, changes in the Company’s gross-to-net deductions balances were as follows (in thousands): Wholesale Distributor Fees, Discounts, and Chargebacks Product Returns Total Balance as of December 31, 2023 $ 21,072 $ 84,616 $ 105,688 Amounts charged against product sales (1) 16,076 19,296 35,372 Payments (26,979) (10,999) (37,978) Balance as of March 31, 2024 $ 10,169 $ 92,913 $ 103,082

Cash, Cash Equivalents, and R_2

Cash, Cash Equivalents, and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
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 sums to the total of such amounts shown in the consolidated statements of cash flows (in thousands): March 31, 2024 December 31, 2023 Cash and cash equivalents $ 480,586 $ 568,505 Restricted cash, current 10,455 10,424 Restricted cash, non-current (1) 4,895 4,881 Cash, cash equivalents, and restricted cash $ 495,936 $ 583,810 (1) Classified as Other non-current assets as of March 31, 2024 and December 31, 2023, on the consolidated balance sheets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of Fair Value Hierarchy	The following table represents the Company’s fair value hierarchy for its financial assets and liabilities (in thousands): Fair Value at March 31, 2024 Fair Value at December 31, 2023 Assets Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Money market funds (1) $ 118,470 $ — $ — $ 171,824 $ — $ — Government-backed securities (1) — 200,000 — — 200,000 — Treasury securities (1) — 46,875 — — 45,622 — Corporate debt securities (1) — 61,428 — — — — Total cash equivalents $ 118,470 $ 308,303 $ — $ 171,824 $ 245,622 $ — Liabilities 5.00% Convertible notes due 2027 $ — $ 109,088 $ — $ — $ 100,909 $ — (1)

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): March 31, 2024 December 31, 2023 Raw materials $ 5,295 $ 6,614 Semi-finished goods 8,984 7,392 Finished goods 1,499 27,690 Total inventory $ 15,778 $ 41,696

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The change in the carrying amounts of goodwill for the three months ended March 31, 2024 was as follows (in thousands): Amount Balance at December 31, 2023 $ 127,454 Currency translation adjustments (4,275) Balance at March 31, 2024 $ 123,179

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Convertible Notes Payable	Total convertible notes payable consisted of the following (in thousands): March 31, 2024 December 31, 2023 5.00% Convertible notes due 2027 $ 175,250 $ 175,250 Unamortized debt issuance costs (6,818) (7,234) Total convertible notes payable $ 168,432 $ 168,016
Schedule of Interest Expense	The interest expense incurred in connection with the convertible notes payable consisted of the following (in thousands): Three Months Ended 2024 2023 Coupon interest $ 2,192 $ 3,206 Amortization of debt issuance costs 416 510 Total interest expense on convertible notes payable $ 2,608 $ 3,716

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
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): Three Months Ended 2024 2023 Cost of sales $ 594 $ 519 Research and development 5,505 13,858 Selling, general, and administrative 5,457 14,270 Total stock-based compensation expense $ 11,556 $ 28,647
Schedule of Option and Appreciation Rights Activity	The following is a summary of stock options and SARs activity under the 2023 Inducement Plan, 2015 Plan, and 2005 Plan for the three months ended March 31, 2024: 2023 Inducement Plan 2015 Plan 2005 Plan Stock Weighted-Average Stock Weighted-Average Stock Weighted-Average Outstanding at December 31, 2023 422,800 $ 10.67 4,787,042 $ 38.10 58,275 $ 119.79 Granted — — 594,367 5.39 — — Exercised — — (142) 5.22 — — Canceled — — (284,823) 37.60 (57,569) 120.01 Outstanding at March 31, 2024 422,800 $ 10.67 5,096,444 $ 34.31 706 $ 102.11 Shares exercisable at March 31, 2024 101,762 $ 11.08 3,411,898 $ 41.21 706 $ 102.11
Schedule of Assumptions Used in Estimation of Fair Value of Stock	The fair value of stock options granted under the 2023 Inducement Plan and the 2015 Plan was estimated at the date of grant using the Black-Scholes option-pricing model with the following assumptions: Three Months Ended 2024 2023 Weighted average Black-Scholes fair value of stock options granted $4.34 $7.19 Risk-free interest rate 4.3% 3.6%-4.0% Dividend yield —% —% Volatility 114.3%-121.1% 127.7%-140.3% Expected term (in years) 3.9-4.4 3.9-5.1
Schedule of Share Based Compensation Restricted Stock Awards Activity	The following is a summary of RSU activity for the three months ended March 31, 2024: 2023 Inducement Plan 2015 Plan Number of Per Share Number of Per Share Outstanding and unvested at December 31, 2023 363,990 $ 10.66 3,714,870 $ 19.43 Granted — — 4,358,623 5.38 Vested (102,797) 10.96 (778,278) 23.96 Forfeited — — (359,910) 20.66 Outstanding and unvested at March 31, 2024 261,193 $ 10.55 6,935,305 $ 10.03

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Costs	During the three months ended March 31, 2024, the restructuring charge recorded by the Company comprised (in thousands): Amount Severance and employee benefit costs $ 4,401 Impairment of assets 1,669 Total Restructuring charge (1) $ 6,070

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	May 10, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) segment $ / shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) $ / shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Foreign currency transaction gain (loss)			$ (5,100)	$ 16,300
Number of business segments | segment			1
Cash and cash equivalents			$ 480,586		$ 568,505
Net income (loss), basic			(147,600)
Net cash provided by (used in) operating activities			$ (83,555)	(325,593)
Common stock, par value per share (in usd per share) | $ / shares			$ 0.01		$ 0.01
Restructuring and related cost, annual impact percent			85%
Severance and employee benefit costs			$ 4,401
Impairment of assets			$ 1,669	$ 0
Sanofi Pasteur Inc. APA | Subsequent Events | Private Placement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from equity method investment	$ 68,800
Sale of stock, number of shares issued in transaction (in shares) | shares	6,880,481
Common stock, par value per share (in usd per share) | $ / shares	$ 0.01
Share, price per share (in usd per share) | $ / shares	$ 10
Forecast | Sanofi Pasteur Inc. APA
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from collaboration and license agreement		$ 568,800
Collaboration agreement upfront payment amount		500,000
Forecast | Sanofi Pasteur Inc. APA | Licensed COVID-19 Products and Royalty Payments
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development, tech transfer, launch, and sales milestone payments		700,000
Forecast | Sanofi Pasteur Inc. APA | First Four Adjuvant Products
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development, tech transfer, launch, and sales milestone payments		200,000
Forecast | Sanofi Pasteur Inc. APA | Adjuvant Products Thereafter
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development, tech transfer, launch, and sales milestone payments		$ 210,000

Revenue - Additional Informatio

Revenue - Additional Information (Details) $ in Thousands, dose in Millions			1 Months Ended	3 Months Ended			12 Months Ended
	Feb. 16, 2024 USD ($)	Dec. 04, 2023 USD ($)	Mar. 31, 2024 USD ($) dose	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) dose	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Mar. 25, 2024 USD ($)	Dec. 31, 2022 USD ($)	Nov. 18, 2022 dose	Sep. 30, 2022 USD ($)
Revenue Recognition
Billed contracts receivable			$ 21,200		$ 21,200		$ 286,400
Unbilled contracts receivable			200		200		10,800
Amount of transaction price not yet satisfied			2,000,000		2,000,000
Deferred revenue			1,082,373		1,082,373	$ 689,826	863,521		$ 549,551
Increase (decrease) in contract with customer, liability					(3,600)
Other current liabilities			242,102		242,102		861,408
Other non-current liabilities			351,722		351,722		33,130
Revenues					93,855	80,951
Deferred revenue			240,900		240,900		241,310
Deferred revenue			841,473		841,473		622,210
Product sales
Revenue Recognition
Deferred revenue			103,082		103,082		105,688
Increase (decrease) in contract with customer, liability					(37,978)
Revenues					82,324	(7,457)
Product sales | North America
Revenue Recognition
Revenues					(6,361)	0
Product sales | Accrued Liabilities
Revenue Recognition
Deferred revenue			97,700		97,700		103,100
Product sales | Accounts Receivable
Revenue Recognition
Deferred revenue			5,400		5,400		2,600
License Fees
Revenue Recognition
Revenues					4,000
Gavi Advance Purchase Agreement- COVAX Facility
Revenue Recognition
Collaboration agreement upfront payment amount			700,000		700,000		696,400
Number of doses to be distributed | dose										350
Settlement Agreement
Revenue Recognition
Litigation settlement, amount awarded to other party	$ 75,000	$ 47,000
Litigation settlement, expense	80,000
Grants receivable	$ 225,000		225,000		225,000
Other current liabilities			80,000		80,000
Other non-current liabilities			320,000		320,000
Settlement payment								$ 42,000			$ 185,000
Settlement Agreement | Forecast
Revenue Recognition
Litigation settlement, expense				$ 400,000
Settlement Agreement | Accrued Liabilities
Revenue Recognition
Settlement payment							68,600
Australian APA
Revenue Recognition
Increase (decrease) in contract with customer, liability			(54,000)
Australian APA | Accrued Liabilities
Revenue Recognition
Settlement payment			6,000		6,000
Canada APA
Revenue Recognition
Deferred revenue			110,600		110,600
Deferred revenue			477,600		477,600
Canada APA | Canada Revenue Agency
Revenue Recognition
Deferred revenue			28,000		28,000
Customer refund liability, current			$ 224,000		224,000
US Government Partnership
Revenue Recognition
Milestone payment recognized							$ 1,800,000
Matrix-M Adjuvant Sales
Revenue Recognition
Revenues					$ 7,500	$ 1,000
European Commissions ("EC") | Minimum
Revenue Recognition
Number of doses to be distributed | dose			20		20
Additional purchase option, number of doses | dose			100		100
European Commissions ("EC") | Maximum
Revenue Recognition
Number of doses to be distributed | dose			100		100
Additional purchase option, number of doses | dose			200		200

Revenue - Accounts Receivable,

Revenue - Accounts Receivable, Unbilled Services, and Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounts receivable:
Accounts receivable, beginning balance	$ 304,916	$ 96,210
Additions	136,510	146,424
Deductions	(412,370)	(115,950)
Accounts receivable, ending balance	29,056	126,684
Allowance for doubtful accounts
Allowance for credit losses, beginning balance	(7,676)	(13,835)
Additions	0	0
Deductions	0	0
Allowance for credit losses, end balance	(7,676)	(13,835)
Deferred revenue
Deferred revenue, beginning balance	863,521	549,551
Additions	225,000	140,324
Deductions	(6,148)	(49)
Deferred revenue, ending balance	1,082,373	689,826
Revenue Recognition
Additions	0	0
Contract with customer, liability, deductions	6,148	$ 49
Joint Committee on Vaccination and Immunization (JCVI)
Deferred revenue
Deductions	(2,200)
Revenue Recognition
Contract with customer, liability, deductions	$ 2,200

Revenue - Schedule of Product R

Revenue - Schedule of Product Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue Recognition
Revenues	$ 93,855	$ 80,951
Product
Revenue Recognition
Revenues	82,324	(7,457)
Product | North America
Revenue Recognition
Revenues	(6,361)	0
Product | Europe
Revenue Recognition
Revenues	90,416	57,267
Product | Rest of the world
Revenue Recognition
Revenues	$ (1,731)	$ (64,724)

Revenue - Schedule of Revenue G

Revenue - Schedule of Revenue Gross to Net Deductions Balances (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Contract with Customer, Liability [Roll Forward]
Deferred revenue, beginning balance	$ 863,521
Amounts charged against product sales(1)	3,400
Payments	(3,600)
Deferred revenue, ending balance	1,082,373
Product sales
Contract with Customer, Liability [Roll Forward]
Deferred revenue, beginning balance	105,688
Amounts charged against product sales(1)	35,372
Payments	(37,978)
Deferred revenue, ending balance	103,082
Product sales | Wholesale Distributor Fees, Discounts, and Chargebacks
Contract with Customer, Liability [Roll Forward]
Deferred revenue, beginning balance	21,072
Amounts charged against product sales(1)	16,076
Payments	(26,979)
Deferred revenue, ending balance	10,169
Product sales | Product Returns
Contract with Customer, Liability [Roll Forward]
Deferred revenue, beginning balance	84,616
Amounts charged against product sales(1)	19,296
Payments	(10,999)
Deferred revenue, ending balance	$ 92,913

Collaboration, License, and S_2

Collaboration, License, and Supply Agreements (Details) $ in Thousands, dose in Millions	1 Months Ended	3 Months Ended
	May 31, 2023	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) installment	Mar. 31, 2023 USD ($)	Mar. 25, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 dose
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty period			15 years
Research and development			$ 92,679	$ 247,101
Takeda Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of doses to be distributed | dose								150
Sanofi Pasteur Inc. APA | Forecast
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration agreement upfront payment amount		$ 500,000
Sanofi Pasteur Inc. APA | Forecast | Licensed COVID-19 Products and Royalty Payments
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development, tech transfer, launch, and sales milestone payments		700,000
Sanofi Pasteur Inc. APA | Forecast | First Four Adjuvant Products
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development, tech transfer, launch, and sales milestone payments		200,000
Sanofi Pasteur Inc. APA | Forecast | Adjuvant Products Thereafter
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development, tech transfer, launch, and sales milestone payments		$ 210,000
Bill & Melinda Gates Medical Research Institute Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, term	3 years
Settlement Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Settlement payment					$ 42,000		$ 185,000
Number of quarterly installment payments | installment			2
Research and development			$ 26,600
Settlement Agreement | Accrued Liabilities
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Settlement payment						$ 68,600

Cash, Cash Equivalents, and R_3

Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 480,586	$ 568,505
Restricted cash, current	10,455	10,424
Restricted cash, non-current	4,895	4,881
Cash, cash equivalents, and restricted cash	$ 495,936	$ 583,810	$ 636,943	$ 1,348,845

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
5.00% Convertible notes due 2027
Liabilities
Debt instrument, interest rate, stated percentage	5%
Level 1
Assets
Total cash equivalents	$ 118,470	$ 171,824
Level 1 | 5.00% Convertible notes due 2027
Liabilities
5.00% Convertible notes due 2027	0	0
Level 1 | Money market funds
Assets
Total cash equivalents	118,470	171,824
Level 1 | Government-backed securities
Assets
Total cash equivalents	0	0
Level 1 | Treasury securities
Assets
Total cash equivalents	0	0
Level 1 | Corporate debt securities
Assets
Total cash equivalents	0	0
Level 2
Assets
Total cash equivalents	308,303	245,622
Level 2 | 5.00% Convertible notes due 2027
Liabilities
5.00% Convertible notes due 2027	109,088	100,909
Level 2 | Money market funds
Assets
Total cash equivalents	0	0
Level 2 | Government-backed securities
Assets
Total cash equivalents	200,000	200,000
Level 2 | Treasury securities
Assets
Total cash equivalents	46,875	45,622
Level 2 | Corporate debt securities
Assets
Total cash equivalents	61,428	0
Level 3
Assets
Total cash equivalents	0	0
Level 3 | 5.00% Convertible notes due 2027
Liabilities
5.00% Convertible notes due 2027	0	0
Level 3 | Money market funds
Assets
Total cash equivalents	0	0
Level 3 | Government-backed securities
Assets
Total cash equivalents	0	0
Level 3 | Treasury securities
Assets
Total cash equivalents	0	0
Level 3 | Corporate debt securities
Assets
Total cash equivalents	$ 0	$ 0

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 5,295		$ 6,614
Semi-finished goods	8,984		7,392
Finished goods	1,499		27,690
Total inventory	15,778		$ 41,696
Provision for excess and obsolete inventory	$ 8,800	$ (12,500)
Firm purchase commitment loss		(7,700)
Inventory, firm purchase commitment, recoveries		$ 800

Goodwill - Schedule of Goodwill

Goodwill - Schedule of Goodwill (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) reporting_unit	Dec. 31, 2023 USD ($) reporting_unit
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reporting unit | reporting_unit	1	1
Goodwill [Roll Forward]
Beginning balance	$ 127,454
Currency translation adjustments	(4,275)
Ending balance	$ 123,179	$ 127,454

Long-Term Debt - Notes Payable

Long-Term Debt - Notes Payable (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Feb. 28, 2023
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (6,818)	$ (7,234)
Total convertible notes payable	168,432	168,016
5.00% Convertible notes due 2027
Debt Instrument [Line Items]
Interest rate			5%
5.00% Convertible notes due 2027 | Unsecured Debt
Debt Instrument [Line Items]
Aggregate principal amount of notes issued	$ 175,250	$ 175,250

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) - USD ($) $ in Millions	1 Months Ended
	Feb. 28, 2023	Mar. 31, 2024	Mar. 31, 2023
5.00% Convertible notes due 2027
Debt Instrument [Line Items]
Interest rate	5%
5.00% Convertible notes due 2027 | Unsecured Debt
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage		6.20%
3.75% Convertible notes due 2023 | Unsecured Debt
Debt Instrument [Line Items]
Repayments of debt	$ 325
Interest rate			3.75%

Long-Term Debt - Interest Expen

Long-Term Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Debt Disclosure [Abstract]
Coupon interest	$ 2,192	$ 3,206
Amortization of debt issuance costs	416	510
Total interest expense on convertible notes payable	$ 2,608	$ 3,716

Stockholders' Deficit (Details)

Stockholders' Deficit (Details) - Common Stock - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Aug. 31, 2023
August 2023 Sales Agreement
Stockholders' Equity
Authorized amount			$ 500,000,000
Remaining unissued capital	$ 242,000,000
June 2021 Sales Agreement
Stockholders' Equity
Sale of stock, consideration received on transaction	$ 0	$ 0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) shares in Millions	1 Months Ended	3 Months Ended
	Jun. 30, 2015	Mar. 31, 2024	Mar. 31, 2023	Jan. 31, 2023	Jun. 30, 2013
Stock-Based Compensation
Stock-based compensation capitalized		$ 0	$ 0
Unrecognized compensation expense		$ 87,000,000
Unrecognized compensation expense, recognition period		2 years
Aggregate intrinsic value, stock options and vesting RSA's		$ 4,500,000	$ 1,500,000
Aggregate intrinsic value, outstanding (less than)		$ 100,000
Remaining term, outstanding (in years)		7 years 1 month 6 days
ESPP
Stock-Based Compensation
Shares available for grant (in shares)		0.2
Authorized (in shares)		1.6			1.2
Percentage increase of shares each anniversary		5%
Subscription rate cap		15%
Maximum discount rate		85%
2023 Inducement Plan
Stock-Based Compensation
Shares available for grant (in shares)				1
Number of shares available for issuance (in shares)		0.2
2015 Plan
Stock-Based Compensation
Number of shares available for issuance (in shares)		2.6
Authorized (in shares)		21
Term (in years)	10 years
Minimum grant price, percent of common stock fair value	100%
Aggregate intrinsic value, exercisable		$ 100,000
Remaining term, exercisable (in years)		6 years
2015 Plan | Minimum
Stock-Based Compensation
Vesting period	1 year
2015 Plan | Maximum
Stock-Based Compensation
Vesting period	4 years

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Compensation expense:
Total stock-based compensation expense	$ 11,556	$ 28,647
Cost of sales
Compensation expense:
Total stock-based compensation expense	594	519
Research and development
Compensation expense:
Total stock-based compensation expense	5,505	13,858
Selling, general, and administrative
Compensation expense:
Total stock-based compensation expense	$ 5,457	$ 14,270

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options and Appreciation Rights (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
2023 Inducement Plan
Stock Options
Outstanding, beginning balance (in shares) | shares	422,800
Granted (in shares) | shares	0
Exercised (in shares) | shares	0
Canceled (in shares) | shares	0
Outstanding, ending balance (in shares) | shares	422,800
Shares exercisable (in shares) | shares	101,762
Weighted-Average Exercise Price
Outstanding, beginning balance (in usd per share) | $ / shares	$ 10.67
Granted (in usd per share) | $ / shares	0
Exercised (in usd per share) | $ / shares	0
Canceled (in usd per share) | $ / shares	0
Outstanding, ending balance (in usd per share) | $ / shares	10.67
Shares exercisable (in usd per share) | $ / shares	$ 11.08
2015 Plan
Stock Options
Outstanding, beginning balance (in shares) | shares	4,787,042
Granted (in shares) | shares	594,367
Exercised (in shares) | shares	(142)
Canceled (in shares) | shares	(284,823)
Outstanding, ending balance (in shares) | shares	5,096,444
Shares exercisable (in shares) | shares	3,411,898
Weighted-Average Exercise Price
Outstanding, beginning balance (in usd per share) | $ / shares	$ 38.10
Granted (in usd per share) | $ / shares	5.39
Exercised (in usd per share) | $ / shares	5.22
Canceled (in usd per share) | $ / shares	37.60
Outstanding, ending balance (in usd per share) | $ / shares	34.31
Shares exercisable (in usd per share) | $ / shares	$ 41.21
2005 Plan
Stock Options
Outstanding, beginning balance (in shares) | shares	58,275
Granted (in shares) | shares	0
Exercised (in shares) | shares	0
Canceled (in shares) | shares	(57,569)
Outstanding, ending balance (in shares) | shares	706
Shares exercisable (in shares) | shares	706
Weighted-Average Exercise Price
Outstanding, beginning balance (in usd per share) | $ / shares	$ 119.79
Granted (in usd per share) | $ / shares	0
Exercised (in usd per share) | $ / shares	0
Canceled (in usd per share) | $ / shares	120.01
Outstanding, ending balance (in usd per share) | $ / shares	102.11
Shares exercisable (in usd per share) | $ / shares	$ 102.11

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Options and Appreciation Rights, Assumptions (Details) - Stock options - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value
Weighted average Black-Scholes fair value of stop options and SARs granted (in usd per share)	$ 4.34	$ 7.19
Risk-free interest rate	4.30%
Risk-free interest rate, minimum		3.60%
Risk-free interest rate, maximum		4%
Dividend yield	0%	0%
Volatility, minimum	114.30%	127.70%
Volatility, maximum	121.10%	140.30%
Minimum
Fair Value
Expected term (in years)	3 years 10 months 24 days	3 years 10 months 24 days
Maximum
Fair Value
Expected term (in years)	4 years 4 months 24 days	5 years 1 month 6 days

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units (Details) - Restricted stock units	3 Months Ended
	Mar. 31, 2024 $ / shares shares
2023 Inducement Plan
Number of Shares
Outstanding and Unvested, beginning balance (in shares) | shares	363,990
Restricted stock units granted (in shares) | shares	0
Restricted stock units vested (in shares) | shares	(102,797)
Restricted stock units forfeited (in shares) | shares	0
Outstanding and Unvested, ending balance (in shares) | shares	261,193
Per Share Weighted- Average Fair Value
Outstanding and Unvested, beginning balance (in usd per share) | $ / shares	$ 10.66
Restricted stock units granted (in usd per share) | $ / shares	0
Restricted stock units vested (in usd per share) | $ / shares	10.96
Restricted stock units forfeited (in usd per share) | $ / shares	0
Outstanding and Unvested, ending balance (in usd per share) | $ / shares	$ 10.55
2015 Plan
Number of Shares
Outstanding and Unvested, beginning balance (in shares) | shares	3,714,870
Restricted stock units granted (in shares) | shares	4,358,623
Restricted stock units vested (in shares) | shares	(778,278)
Restricted stock units forfeited (in shares) | shares	(359,910)
Outstanding and Unvested, ending balance (in shares) | shares	6,935,305
Per Share Weighted- Average Fair Value
Outstanding and Unvested, beginning balance (in usd per share) | $ / shares	$ 19.43
Restricted stock units granted (in usd per share) | $ / shares	5.38
Restricted stock units vested (in usd per share) | $ / shares	23.96
Restricted stock units forfeited (in usd per share) | $ / shares	20.66
Outstanding and Unvested, ending balance (in usd per share) | $ / shares	$ 10.03

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Contingency [Line Items]
Federal, state and local, income tax expense (benefit)	$ 2.3	$ 1.2
Capital Loss Carryforward
Income Tax Contingency [Line Items]
Net operating loss carryforwards	11.3
Domestic
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 2,400

Commitment and Contingencies (D

Commitment and Contingencies (Details) $ in Thousands, dose in Millions					3 Months Ended
	Feb. 16, 2024 USD ($)	Dec. 04, 2023 USD ($)	Dec. 28, 2022 lawsuit	Dec. 12, 2022 defendant	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) installment payment	Mar. 31, 2023 USD ($)	Mar. 25, 2024 USD ($)	Dec. 31, 2023 USD ($)	Nov. 18, 2022 dose	Sep. 30, 2022 USD ($)
Loss Contingencies [Line Items]
Number of defendants | defendant				2
Period to answer				14 days
Loss contingency accrual						$ 47,000			$ 47,000
Number of lawsuits filed | lawsuit			8
Research and development						92,679	$ 247,101
Gavi Advance Purchase Agreement- COVAX Facility
Loss Contingencies [Line Items]
Number of doses to be distributed | dose										350
Purchase agreement, number of vaccine doses | dose										2
Collaboration agreement upfront payment amount						700,000			696,400
Settlement Agreement
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party	$ 75,000	$ 47,000
Litigation settlement, expense	80,000
Grants receivable	$ 225,000					$ 225,000
Settlement payment								$ 42,000			$ 185,000
Number of quarterly installment payments | installment						2
Number of settlement payments | payment						2
Settlement agreement, installment payment						$ 34,300
Research and development						$ 26,600
Settlement Agreement | Forecast
Loss Contingencies [Line Items]
Litigation settlement, expense					$ 400,000
Settlement Agreement | Accrued Liabilities
Loss Contingencies [Line Items]
Settlement payment									$ 68,600

Restructuring - Schedule of Imp

Restructuring - Schedule of Impairment Charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Severance and employee benefit costs	$ 4,401
Impairment of assets	1,669	$ 0
Total Restructuring charge	6,070
Research and development
Restructuring Cost and Reserve [Line Items]
Total Restructuring charge	1,600
Selling, general, and administrative
Restructuring Cost and Reserve [Line Items]
Total Restructuring charge	$ 4,500

Restructuring - Narrative (Deta

Restructuring - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Payments for severance and employee benefit costs	$ 3,900
Severance and employee benefit costs	4,401
Impairment of assets	1,669	$ 0
Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Severance and employee benefit costs	$ 500

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	May 10, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Subsequent Event [Line Items]
Common stock, par value per share (in usd per share)			$ 0.01	$ 0.01
Sanofi Pasteur Inc. APA | Private Placement | Subsequent Events
Subsequent Event [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	6,880,481
Common stock, par value per share (in usd per share)	$ 0.01
Share, price per share (in usd per share)	$ 10
Proceeds from equity method investment	$ 68.8
Sanofi Pasteur Inc. APA | Forecast
Subsequent Event [Line Items]
Collaboration agreement upfront payment amount		$ 500
Sanofi Pasteur Inc. APA | Forecast | Licensed COVID-19 Products and Royalty Payments
Subsequent Event [Line Items]
Development, tech transfer, launch, and sales milestone payments		700
Sanofi Pasteur Inc. APA | Forecast | First Four Adjuvant Products
Subsequent Event [Line Items]
Development, tech transfer, launch, and sales milestone payments		200
Sanofi Pasteur Inc. APA | Forecast | Adjuvant Products Thereafter
Subsequent Event [Line Items]
Development, tech transfer, launch, and sales milestone payments		$ 210