Icosavax (ICVX) 10-K 30 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 28, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Entity Registrant Name	ICOSAVAX, INC.
Entity Central Index Key	0001786255
Entity File Number	001-40655
Entity Tax Identification Number	82-3640549
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Address Address Line1	1616 Eastlake Avenue E.
Entity Address, Address Line Two	Suite 208
Entity Address City Or Town	Seattle
Entity Address, State and Province	WA
Entity Incorporation State Country Code	DE
Entity Address Postal Zip Code	98102
Local Phone Number	737-0085
City Area Code	206
Security12b Title	Common Stock, $0.0001 par value per share
Trading Symbol	ICVX
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		39,724,980
Entity Public Float			$ 0
Auditor Name	Ernst & Young LLP
Auditor Location	Seattle, Washington
Auditor Firm ID	42
Documents Incorporated by Reference	Certain sections of the registrant’s definitive proxy statement for the 2022 annual meeting of stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash	$ 279,082	$ 13,114
Restricted cash	1,642	2,384
Prepaid expenses and other current assets	5,829	662
Total current assets	286,553	16,160
Property and equipment, net	1,076	10
Total assets	287,629	16,170
Current liabilities:
Accounts payable	3,899	1,918
Accrued and other current liabilities	4,757	1,532
Deferred revenue	582	2,384
Total current liabilities	9,238	5,834
Long-term convertible promissory note	0	4,947
Embedded derivative liability	0	1,604
Other noncurrent liabilities	171	426
Total liabilities	9,409	12,811
Commitments and contingencies (Note 2)
Stockholders' equity (deficit):
Preferred stock, $0.0001 par value; 50,000,000 and no shares authorized at December 31, 2021 and 2020, respectively; no shares issued and outstanding at either December 31, 2021 or 2020	0	0
Common stock, $0.0001 par value; 500,000,000 and 78,000,000 shares authorized at December 31, 2021 and 2020, respectively; 39,429,103 and 3,596,936 shares issued as of December 31, 2021 and 2020, respectively; 39,175,172279 and 2,639,026 shares outstanding as of December 31, 2021 and December 31, 2020, respectively	5	2
Additional paid-in capital	372,284	393
Accumulated deficit	(94,069)	(27,098)
Total stockholders' equity (deficit)	278,220	(26,703)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	287,629	16,170
Total liabilities	9,409	12,811
Convertible Preferred Stock [Member]
Current liabilities:
Convertible preferred stock, $0.0001 par value; no shares authorized at December 31, 2021 and 54,039,749 shares authorized at December 31, 2020; no shares issued and outstanding at December 31, 2021 and 32,198,879 shares issued and outstanding at December 31, 2020; $0 and $30,007 aggregate liquidation preference at December 31, 2021 and 2020, respectively	$ 0	$ 30,062

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Convertible preferred stock, aggregate liquidation preference		$ 30,007
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	50,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	78,000,000
Common stock, shares issued	39,429,103	3,596,936
Common Stock Shares Outstanding	39,175,279	2,639,026
Convertible Preferred Stock [Member]
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	54,039,749
Convertible preferred stock, shares issued	0	32,198,879
Convertible preferred stock, shares outstanding	0	32,198,879
Convertible preferred stock, aggregate liquidation preference	$ 0	$ 30,007

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Grant revenue	$ 7,802	$ 1,616
Operating expenses:
Research and development	38,776	17,667
General and administrative	34,887	2,659
Total operating expenses	73,663	20,326
Loss from operations	(65,861)	(18,710)
Other income (expense):
Change in fair value of embedded derivative liability	(205)	187
Loss on extinguishment of convertible promissory note	(754)	0
Interest and other expense	(151)	(331)
Total other expense	(1,110)	(144)
Net loss and comprehensive loss	$ (66,971)	$ (18,854)
Net loss per share, basic and diluted	$ (3.73)	$ (8.40)
Weighted-average common shares outstanding, basic and diluted	17,965,894	2,245,223

Statements of Convertible Prefe

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Deficit [Member]	Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]Series A-1 Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]Series B-1 Convertible Preferred Stock [Member]
Convertible preferred stock, Beginning Balance (in shares) at Dec. 31, 2019					32,198,879
Convertible preferred stock, Beginning Balance at Dec. 31, 2019					$ 30,062
Beginning Balance (in shares) at Dec. 31, 2019		1,901,656
Beginning Balance at Dec. 31, 2019	$ (8,243)	$ 1		$ (8,244)
Shares released from restriction upon vesting of early-exercised stock options (in shares)		267,894
Shares released from restriction upon vesting of early-exercised stock options	137	$ 1	$ 136
Vesting of shares of restricted common stock		469,476
Stock-based compensation	257		257
Net loss and comprehensive loss	(18,854)			(18,854)
Convertible preferred stock, Ending Balance (in shares) at Dec. 31, 2020					32,198,879
Convertible preferred stock, Ending Balance at Dec. 31, 2020					$ 30,062
Ending Balance (in shares) at Dec. 31, 2020		2,639,026
Ending Balance at Dec. 31, 2020	(26,703)	$ 2	393	(27,098)
Shares released from restriction upon vesting of early-exercised stock options (in shares)		344,179
Shares released from restriction upon vesting of early-exercised stock options	203		203
Vesting of shares of restricted common stock		469,493
Issuance of Series convertible preferred stock, (in shares)						21,944,874	32,958,612
Issuance of Series convertible preferred stock						$ 21,004	$ 92,630
Issuance of Series B-2 convertible preferred stock from convertible note (in shares)					2,805,850
Issuance of Series B-2 convertible preferred stock from convertible note					$ 7,917
Initial public offering, net of issuance costs, (in shares)		13,953,332
Initial public offering, net of issuance costs	190,737	$ 1	190,736
Conversion of convertible preferred stock into common stock, (in shares)		21,634,898			(89,908,215)
Conversion of convertible preferred stock into common stock	151,613	$ 2	151,611		$ (151,613)
Issuance of common stock for Employee Stock Purchase Plan, (in shares)		16,606
Issuance of common stock for Employee Stock Purchase Plan	$ 212		212
Exercise of common stock options, (in shares)	227,333	117,745
Exercise of common stock options	$ 98		98
Stock-based compensation	29,031		29,031
Net loss and comprehensive loss	(66,971)			(66,971)
Convertible preferred stock, Ending Balance (in shares) at Dec. 31, 2021					0
Convertible preferred stock, Ending Balance at Dec. 31, 2021					$ 0
Ending Balance (in shares) at Dec. 31, 2021		39,175,279
Ending Balance at Dec. 31, 2021	$ 278,220	$ 5	$ 372,284	$ (94,069)

Statements of Convertible Pre_2

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)$ / shares
IPO [Member]
Payments of Stock Issuance Costs	$ 18.6
Series A-1 Convertible Preferred Stock [Member]
Issuance of convertible preferred stock per share | $ / shares	$ 0.9615
Convertible Preferred Stock Issuance Cost	$ 0.1
Series B-1 Convertible Preferred Stock [Member]
Issuance of convertible preferred stock per share | $ / shares	$ 2.82172
Convertible Preferred Stock Issuance Cost	$ 0.3

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net loss and comprehensive loss	$ (66,971)	$ (18,854)
Adjustments to reconcile net loss to cash used in operating activities:
Stock-based compensation	29,031	257
Depreciation	82	1
Non-cash interest expense	264	417
Change in fair value of embedded derivative liability	(205)	187
Loss on extinguishment of convertible promissory note	754	0
Changes in operating assets and liabilities:
Prepaids and other current assets	(5,167)	(453)
Accounts payable	1,839	1,119
Accrued and other current liabilities	3,225	1,108
Deferred revenue	(1,802)	2,384
Net cash used in operating activities	(38,540)	(14,208)
Investing activities:
Purchases of property and equipment	(1,006)	(11)
Net cash used in investing activities	(1,006)	(11)
Financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	113,634	0
Proceeds from initial public offering, net of offering costs	190,738	0
Proceeds from issuance of convertible promissory notes, net of issuance costs	0	6,464
Proceeds from exercise of stock options, including early exercise	400	174
Net cash provided by financing activities	304,772	6,638
Net increase (decrease) in cash and restricted cash	265,226	(7,581)
Cash and restricted cash at beginning of period	15,498	23,079
Cash and restricted cash at end of period	280,724	15,498
Supplemental disclosure of noncash activities
Conversion of preferred stock to common stock	151,613
Purchases of property and equipment included in accounts payable	$ 142

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. Description of Business Organization Icosavax, Inc. (the “Company”) was incorporated in the state of Delaware on November 1, 2017, and is located in Seattle, Washington. The Company is focused on the research and development of vaccines against infectious diseases. The Company was founded on computationally designed virus-like particle technology, exclusively licensed for a variety of infectious disease indications from the Institute for Protein Design at the University of Washington. The Company’s business involves inherent risks. These risks include, among others, dependence on key personnel, licensors and third-party service providers, patentability of the Company’s products and processes, and clinical efficacy of the Company’s products under development. In addition, any of the technologies covering the Company’s existing products under development could become obsolete or diminished in value by discoveries and developments at other organizations. In July 2021, the Company effected a 1-for-4.1557 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of the Company’s convertible preferred stock. Accordingly, all share and per share amounts for all periods presented in the accompanying financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the convertible preferred stock conversion ratios. On August 2, 2021, the Company completed its initial public offering (“IPO”) pursuant through which it issued 12,133,333 shares of its common stock at a public offering price of $ 15.00 per share, and on August 2, 2021, the Company sold an additional 1,819,999 shares pursuant to the exercise by the underwriters of their option to purchase additional shares. The Company received net proceeds from its IPO, inclusive of the exercise by the underwriters of their option to purchase additional shares, of $ 190.7 million, after deducting underwriting discounts and commissions and offering expenses. Upon the closing of the IPO, all 89,908,215 shares of the then outstanding convertible preferred stock automatically converted into 21,634,898 shares of common stock. Liquidity The Company had an accumulated deficit of $ 94.1 million, cash of $ 279.1 million, and restricted cash of $ 1.6 million at December 31, 2021. Management believes the Company has sufficient capital to execute its strategic plan and fund operations through at least the next twelve months from the date these financial statements are issued. The Company has devoted substantially all of its resources to organizing and staffing the Company, business planning, raising capital, in-licensing intellectual property rights, developing vaccines candidates, scaling up manufacturing of vaccine candidates, and preparing for its ongoing and planned preclinical studies and clinical trials. The Company has a limited operating history, and the sales and income potential of its business is unproven. The Company has incurred net losses and negative cash flows from operating activities since its inception and expects to continue to incur net losses into the foreseeable future as it continues the development of its vaccine candidates. From inception to December 31, 2021, the Company has funded its operations primarily through the sale of its convertible preferred stock and common stock. As the Company continues to pursue its business plan, it expects to finance its operations through equity offerings, debt financings or other capital sources, including potential strategic collaborations, licenses, and other similar arrangements. However, there can be no assurance that any additional financing or strategic transactions will be available to the Company on acceptable terms, if at all. If events or circumstances occur such that the Company does not obtain additional funding, it may need to delay, reduce or eliminate its product development or future commercialization efforts, which could have a material adverse effect on the Company’s business, results of operations or financial condition. The accompanying financial statements do not include any adjustments that might be necessary if the Company were unable to continue as a going concern.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) promulgated by the Financial Accounting Standards Board (“FASB”). Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported balances of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates are used for, but not limited to, stock-based compensation, derivative liability, the timing of research and development accruals, and income taxes. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. The full extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including expenses, clinical trials and research and development costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, as well as the economic impact on local, regional, national and international markets. The Company has considered potential impacts arising from the COVID-19 pandemic and is not presently aware of any events or circumstances that would require the Company to update its estimates, judgments or revise the carrying value of its assets or liabilities. Concentration of Credit Risk Financial instruments which potentially subject the Company to significant concentration of credit risk consist of cash and restricted cash. The Company is exposed to credit risk from its deposits of cash in excess of amounts insured by the Federal Deposit Insurance Corporation. The Company maintains an Insured Cash Sweep account where balances are maintained in interest bearing demand accounts. The Company has not experienced any losses on its deposits of cash since inception, and management believes that the Company is not exposed to significant credit risk due to the financial positions of the respective depository institutions in which those deposits are held . Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. The Company’s comprehensive loss was the same as its reported net loss for all periods presented. Fair Value of Financial Instruments The accounting guidance defines fair value, establishes a consistent framework for measuring fair value, and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The carrying amounts of all cash, restricted cash, prepaid expenses and other assets, accounts payable, and accrued and other current liabilities are considered to be representative of their respective fair values due to their short maturities. The carrying values of the derivative liability of $ 1.6 million (level 3 fair value) and the convertible promissory note of $ 4.9 million in the accompanying balance sheet at December 31, 2020 approximate fair value because they collectively converted into 2,805,850 shares of Series B convertible preferred stock in March 2021. Cash Cash represents funds in the Company’s operating bank account. The Company has no cash equivalents. Restricted Cash The Company’s restricted cash includes payments received under the Grant Agreement (as defined in Note 4) with the Bill & Melinda Gates Foundation (“BMGF”) under which the Company was awarded a grant of up to $ 10.0 million. The Company will utilize the Grant Agreement funds as it incurs expenses for services performed under the agreement. Restricted cash also includes cash collateral supporting the standby letter of credit discussed in "Leases" below. Property and equipment, net Property and equipment, net is stated at cost, net of accumulated depreciation and is depreciated using the straight-line method over the estimated useful lives of the assets (generally two to five years ). Impairment of Long-Lived Assets The Company regularly reviews the carrying value and estimated lives of its long-lived assets, including property and equipment to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. Should an impairment exist, the impairment loss would be measured based on the excess over the carrying amount of the asset’s fair value. The Company has no t recognized any impairment losses from inception through December 31, 2021. Derivative Liability, Convertible Notes Discount and Amortization The Company’s convertible note (see Note 7) had conversion and redemption features that met the definition of an embedded derivative and were therefore subject to bifurcation and derivative accounting. The initial recognition of the fair value of the derivative resulted in a discount to the convertible note, with a corresponding derivative liability. The discount to the convertible note was amortized using the effective interest method. The amortization of the discount is included in interest and other income (expense) in the statements of operations and comprehensive loss. The derivative liability related to these features was recorded at estimated fair value and remeasured on a recurring basis. Any changes in fair value were reflected as change in fair value of derivative liability in the statements of operations and comprehensive loss at each reporting date while such instruments were outstanding. The derivative liability was settled in March 2021 upon conversion of the underlying convertible note into Series B convertible preferred stock, resulting in a loss on extinguishment of convertible promissory note . Leases At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use asset upon commencement of the lease using the implicit rate or a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. The Company additionally evaluates leases at their inception to determine if they are to be accounted for as an operating lease or a finance lease. A lease is accounted for as a finance lease if it meets one of the following five criteria: the lease has a purchase option that is reasonably certain of being exercised, the present value of the future cash flows is substantially all of the fair market value of the underlying asset, the lease term is for a significant portion of the remaining economic life of the underlying asset, the title to the underlying asset transfers at the end of the lease term, or if the underlying asset is of such a specialized nature that it is expected to have no alternative uses to the lessor at the end of the term. Leases that do not meet the finance lease criteria are accounted for as an operating lease. Operating lease assets represent a right to use an underlying asset for the lease term and operating lease liabilities represent an obligation to make lease payments arising from the lease. Operating lease liabilities with a term greater than one year and their corresponding right-of-use assets are recognized on the balance sheet at the commencement date of the lease based on the present value of lease payments over the expected lease term. Certain adjustments to the right-of-use asset may be required for items such as initial direct costs paid or incentives received. As the Company’s leases do not typically provide an implicit rate, the Company utilizes the appropriate incremental borrowing rate, determined as the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and in a similar economic environment. Lease cost is recognized on a straight-line basis over the lease term and variable lease payments are recognized as operating expenses in the period in which the obligation for those payments is incurred. Variable lease payments primarily include common area maintenance, utilities, real estate taxes, insurance, and other operating costs that are passed on from the lessor in proportion to the space leased by the Company. The Company has elected the practical expedient to not separate lease and non-lease components. In January 2020, and amended in March 2020, the Company entered into a lab license agreement for office and lab space in Seattle, Washington. The lab license agreement is twelve months and provides for renewal options. The monthly base rent is approximately $ 16,000 . The lab license agreement is considered short-term and therefore, no right-of-use asset or lease liability has been recorded. In December 2021, the Company entered into a lease agreement for corporate office and lab space in Seattle, Washington. The Company took possession of certain leased space at various dates in January 2022 and March 2022. The lease agreement is five years and 3 months and provides for a one-time option to extend for a period of five additional years. The monthly base rent will be $ 0.2 million for the first year and will increase by 3.0 % per year over the initial term. In addition, the Company is obligated to pay for common area maintenance and other costs. Under the terms of the lease agreement, the Company is required to maintain a standby letter of credit of $ 1.1 million at the execution of the lease agreement, reduced to $ 0.9 million at the first anniversary, and further reduced to $ 0.7 million at the second anniversary of the lease. As of December 31, 2021, the Company had not taken control of the space and the lease term had not commenced; therefore, no right-of-use asset or lease liability has been recognized. Grant Revenue The Company’s revenue consists of revenue under its Grant Agreement with BMGF (see Note 4). The Company is reimbursed for certain costs that support development activities, including the Company’s clinical trial notification (“CTN”) preparations for and planned first-in-human Phase 1/2 clinical trial of COVID-19 RBD VLP vaccine in Australia. The Company’s Grant Agreement does not provide a direct economic benefit to BMGF. Rather, the Company entered into an agreement with BMGF to make a certain amount of any resulting vaccine available and accessible at affordable pricing to people in certain low- and middle-income countries. The Company assessed this cost reimbursement agreement to determine if the agreement should be accounted for as an exchange transaction or a contribution. Such an agreement is accounted for as a contribution if the resource provider does not receive commensurate value in return for the assets transferred. Contributions are recognized as grant revenue when all donor-imposed conditions have been met. As BMGF ultimately determines if milestones under the agreement are met and if funding should continue, there may be a difference in timing between when research and development expenses are incurred and when grant revenue is recognized. Accrued Research and Development Expense The Company is required to estimate its obligation for expenses incurred under contracts with vendors, consultants, and contract research organizations, in connection with conducting research and development activities. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company reflects research and development expenses in its financial statements by recognizing those expenses in the periods in which services and efforts are expended. The Company accounts for these expenses according to the progress of the preclinical study or clinical trial, as measured by the timing of various aspects of the study, trial or related activities. The Company determines accrual estimates through review of the underlying contracts along with preparation of financial models taking into account discussions with research and other key personnel and third-party service providers as to the progress of studies or trials, or other services being conducted. To date, the Company has had no material differences between its estimates of such expenses and the amounts actually incurred. During the course of a study or trial, the Company adjusts its expense recognition if actual results differ from its estimate. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed or services are performed. Research and Development Research and development costs are expensed as incurred and consist primarily of external and internal costs related to the development of vaccine candidates, including salaries and benefits, stock-based compensation, facilities and depreciation, contracted research, consulting arrangements, and other expenses incurred to sustain the Company’s research and development programs . Interest Income Interest income consists of interest income earned on interest bearing demand accounts. Liability for Early Exercise of Stock Options Certain individuals were granted the ability to early exercise their stock options. The shares of common stock issued from the early exercise of unvested stock options are restricted and continue to vest in accordance with the original vesting schedule. The Company has the option to repurchase any unvested shares at the original purchase price upon any voluntary or involuntary termination. The shares purchased by the employees and non-employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be outstanding until those shares vest. The cash received in exchange for exercised and unvested shares related to stock options granted is recorded as a liability for the early exercise of stock options on the accompanying balance sheets and will be reclassified as common stock and additional paid-in capital as the shares vest. Unvested shares issued under early exercise provisions subject to repurchase by the Company totaled 253,824 and 488,226 shares as of December 31, 2021 and 2020, respectively. As of December 31, 2021 and 2020, the Company had $ 0.2 million and $ 0.2 million respectively, of amounts related to shares issued with repurchase rights classified as other noncurrent liabilities in the accompanying balance sheets. Stock-Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee, officer, director and non-employee stock option grants, estimated in accordance with the applicable accounting guidance, recognized on a straight-line basis over the vesting period. The vesting period generally approximates the expected service period of the awards. The Company recognizes forfeitures as they occur. The Black-Scholes option pricing model uses inputs which are assumptions that generally require judgment. These assumptions include: ▪ Fair Value of Common Stock . Prior to the Company’s IPO, the grant date fair market value of the shares of common stock underlying stock options was historically determined by the Company’s board of directors. Because there was no public market for the Company’s common stock, the board of directors exercised reasonable judgment and considered a number of objective and subjective factors to determine the best estimate of the fair market value, which included contemporaneous valuations performed by an independent third-party, the Company’s results of operations and financial position, including its levels of available capital resources, its stage of development and material risks related to the Company’s business, progress of the Company’s research and development activities, the Company’s business conditions and projections, the lack of marketability of the Company’s common stock and preferred stock as a private company, the prices at which the Company sold shares of its convertible preferred stock to outside investors in arms-length transactions, the rights, preferences and privileges of the Company’s redeemable convertible preferred stock relative to those of its common stock, the analysis of initial public offerings and the market performance of similar companies in the biopharmaceutical industry, the likelihood of achieving a liquidity event for the Company’s securityholders, such as an initial public offering or a sale of the Company, given prevailing market conditions, the hiring of key personnel and the experience of management, trends and developments in the Company’s industry, and external market conditions affecting the life sciences and biopharmaceutical industry sectors. Subsequent to the Company’s IPO, the grant date fair value of the Company’s common stock is determined based on its closing price. ▪ Expected Term . The expected term represents the period that the options granted are expected to be outstanding. The expected term of stock options issued is determined using the simplified method (based on the average of the vesting term and the original contractual term) as the Company has concluded that its stock option exercise history does not provide a reasonable basis upon which to estimate expected term. ▪ Expected Volatility . Given the Company’s limited historical stock price volatility data, the Company derived the expected volatility from the average historical volatilities over a period approximately equal to the expected term of comparable publicly traded companies within the Company’s peer group that were deemed to be representative of future stock price trends as the Company has limited trading history for its common stock. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. ▪ Risk-Free Interest Rate . The risk-free interest rate is based on the U.S. Treasury zero-coupon issues in effect at the time of grant for periods corresponding with the expected term of the options. ▪ Expected Dividend Yield . The Company never paid dividends on its common stock and do not anticipate paying any dividends in the foreseeable future. Therefore, the Company used an expected dividend yield of zero. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date. Commitments and Contingencies The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has been incurred, and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount the Company accrues the minimum amount in the range. In the event the Company becomes subject to claims or suits arising in the ordinary course of business, the Company would accrue a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. The Company has not recorded any such liabilities at either December 31, 2021 or 2020. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. As of December 31, 2021 and 2020, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes may result in a change in the estimated annual effective tax rate. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. As of December 31, 2021, the Company had no accrued interest or penalties. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and common stock equivalents outstanding for the period. Common stock equivalents are only included when their effect is dilutive. The Company’s potentially dilutive securities include outstanding stock options under the Company’s equity incentive plan and have been excluded from the computation of diluted net loss per share as they would be anti-dilutive to the net loss per share. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position. The following tables summarize the computation of the basic and diluted net loss per share (in thousands, except share and per share data): Year Ended 2021 2020 Numerator: Net loss $ ( 66,971 ) $ ( 18,854 ) Denominator: Weighted-average common shares outstanding, basic and diluted 18,587,782 3,517,671 Less: Weighted-average unvested common stock ( 621,888 ) ( 1,272,448 ) Weighted-average shares used to compute net loss per share, basic and 17,965,894 2,245,223 Net loss per share, basic and diluted $ ( 3.73 ) $ ( 8.40 ) The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive. Year Ended 2021 2020 Series A convertible preferred stock — 32,198,879 Common stock options 6,591,727 641,427 ESPP shares 16,606 — Unvested common stock 253,824 957,711 Total 6,862,157 33,798,017 Segments The Company has determined that it operates and manages one operating segment, which is the business of researching and developing vaccines against infectious diseases. The Company’s chief operating decision maker, its chief executive officer, reviews financial information on an aggregate basis for the purpose of allocating resources. All assets of the Company are located in the United States. Recent Accounting Pronouncements Recently Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, Income Taxes—Simplifying the Accounting for Income Taxes (“ASU 2019-12”). The new guidance simplifies the accounting for income taxes by removing several exceptions in the current standard and adding guidance to reduce complexity in certain areas, such as requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. The new standard is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022 for all non-public entities, with early adoption permitted, and is effective for fiscal years beginning after December 15, 2020, including interim periods within those annual periods for public entities. Early adoption is permitted. The Company adopted ASU 2019-12 on January 1, 2021 and the standard did not have a material impact on its financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Disclosures	3. Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1 —Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 —Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. Level 3 —Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e. supported by little or no market activity). No transfers between levels have occurred during the periods presented. The following table summarizes financial liabilities that the Company measured at fair value on a recurring basis, classified in accordance with the fair value hierarchy (in thousands): Fair Value Measurements at Report Date Using Total (Level 1) (Level 2) (Level 3) As of December 31, 2020 Embedded derivative liability $ ( 1,604 ) $ — $ — $ ( 1,604 ) There were no assets or liabilities measured at fair value on a recurring basis as of December 31, 2021. As further described in Note 7, the Company issued a convertible promissory note in August 2020. The convertible promissory note contained certain features that met the definition of a derivative and were required to be bifurcated. The Company has accounted for these as a single derivative comprising all the features requiring bifurcation. The fair value of the derivative liability was estimated using a scenario-based analysis comparing the probability-weighted present value of the convertible promissory note payoff at maturity with and without the bifurcated features. The Company considered possible outcomes available to the noteholders, including various financing dissolution scenarios. In addition, the probabilities applied to various scenarios, the key unobservable inputs are the time to liquidity for each scenario, and the discount rate. The following table summarizes information about the significant unobservable inputs used in the fair value measurements for the derivative liability: March 19, 2021 December 31, 2020 August 20, 2020 Probability of financing 100 % 90 % 90 % Probability of dissolution — 10 % 10 % Time to liquidity (years) — 0.50 - 1.00 0.83 - 1.33 Discount rate 7.6 % 8.3 % 11.9 % The Company adjusted the carrying value of the derivative liability within the convertible promissory note to the estimated fair value at each reporting date, with any related increases or decreases in the fair value recorded as change in fair value of derivative liability in the statements of operations and comprehensive loss. For the year ended December 31, 2021, the Company recognized $ 0.2 million of other income in the statements of operations and comprehensive loss related to increases in the fair value of the embedded derivative liability. For the year ended December 31, 2020, the Company recognized $ 0.2 million of other income in the statements of operations and comprehensive loss related to decreases in the fair value of the embedded derivative liability. On March 19, 2021, in connection with the closing of the Series B convertible preferred stock financing, the convertible promissory note (including accrued interest) and derivative liability converted into 2,805,850 shares of Series B-2 convertible preferred stock. As a result of the conversion, the Company recorded a loss on extinguishment of convertible promissory note of $ 0.8 million in other expense in the statements of operations and comprehensive loss for the year ended December 31, 2021, which included the write off of unamortized debt issuance costs. The following table provides a reconciliation of the fair value of the derivative liability using Level 3 significant unobservable inputs (in thousands): Derivative Liability Fair value at December 31, 2019 $ — Fair value of derivative liability at issuance of convertible promissory note ( 1,791 ) Change in fair value of derivative liability (Note 7) 187 Fair value at December 31, 2020 ( 1,604 ) Change in fair value of embedded derivative liability ( 205 ) Reclassification of derivative liability into convertible preferred stock resulting from conversion of convertible promissory note 1,809 Fair value at December 31, 2021 $ —

Grant Agreement

Grant Agreement	12 Months Ended
	Dec. 31, 2021
Grant Agreement [Abstract]
Grant Agreement	4. Grant Agreement Bill & Melinda Gates Foundation Grant Agreement In support of the Company’s development of a COVID-19 vaccine for pandemic use, in September 2020, the Company entered into the grant agreement (the “Grant Agreement”) with the Bill & Melinda Gates Foundation (“BMGF”), under which it was awarded a grant totaling up to $ 10.0 million (the “Grant”). The Grant supported development activities, including the Company’s regulatory filing preparations and planned Phase 1 clinical trial. Unless terminated earlier by BMGF, the Grant Agreement will continue in effect until March 31, 2022. The Company concurrently entered into a Global Access Commitments Agreement (“GACA”) with BMGF as part of the Grant Agreement. Under the terms of the GACA, among other things, the Company agreed to make a certain amount of its COVID-19 vaccine available and accessible at affordable pricing to people in certain low- and middle-income countries, if the vaccine is commercialized. Payments received in advance that are related to future performance are deferred and recognized as revenue when the research and development activities are performed. Cash payments received under the Grant Agreement are restricted as to their use until eligible expenditures are incurred. At December 31, 2021, the Company had $ 0.6 million of restricted cash and deferred revenue, and at December 31, 2020, had $ 2.3 million of restricted cash and deferred revenue, representing funds received from BMGF and the Company's estimate of costs to be reimbursed and revenue to be recognized, respectively, in the next twelve months under the Grant Agreement. During the years ended December 31, 2021 and 2020, the Company received $ 6.0 million and $ 4.0 million in funding, respectively, from BMGF. During the years ended December 31, 2021 and 2020, the Company recognized revenue from the Grant Agreement of $ 7.8 million and $ 1.6 million, respectively, and has recognized approximately $ 9.4 million in revenue since the inception of the Grant Agreement. As of December 31, 2021, the Company has received the full $ 10.0 million in funding under the Grant Agreement.

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	5. Balance Sheet Details Property and equipment, net, consists of the following (in thousands): As of December 31, 2021 2020 Laboratory equipment $ 856 $ 11 Construction in progress 303 — Property and equipment, cost 1,159 11 Accumulated depreciation ( 83 ) ( 1 ) Property and equipment, net $ 1,076 $ 10 Depreciation expense was $ 0.1 million for the year ended December 31, 2021, and was a negligible amount for the year ended December 31, 2020. Accrued and other current liabilities consist of the following (in thousands): As of December 31, 2021 2020 Taxes payable $ — $ 91 Accrued paid time off 342 137 Accrued bonus 2,216 696 Other accrued liabilities 1,977 608 Accrued 401k 156 — ESPP liability 66 — Total accrued and other current liabilities $ 4,757 $ 1,532

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2021
License Agreements [Abstract]
License Agreements	6. License Agreements License Agreement with the National Institutes of Health On June 28, 2018, the Company entered into a non-exclusive patent license agreement (the “NIH Agreement”) with a U.S. government entity, the National Institutes of Health, represented by National Institute of Allergy and Infectious Disease (“NIAID”). The NIH Agreement was amended in September 2018 and September 2020. Under the NIH Agreement, the Company obtained a non-exclusive, worldwide, royalty-bearing, sublicensable license under certain NIAID patent rights, and transfer of know-how and biological materials for use in adjuvanted or non-adjuvanted vaccines for the prevention, cure, or treatment of RSV and metapneumovirus infection in humans. Under the NIH Agreement, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. In consideration of the rights granted to the Company under the NIH Agreement, the Company paid a licensing fee upon execution of the NIH Agreement of $ 100,000 , and will pay annual minimum royalty payments starting in the second year after the initial sale of each licensed product which can be credited against any earned royalties due for sales made in the year. There are milestone payments due upon the completion of certain development, regulatory, and commercial milestones for the licensed products in the future. The Company is obligated to pay aggregate potential milestone payments of up to $ 2.1 million with respect to future development and regulatory based milestones, and up to $ 6.5 million with respect to future sales milestones following commercialization. Additionally, the Company has agreed to pay a tiered royalty of a low single digit percentage on net sales of all products applicable to the license. Additional royalties would be due in connection with sublicenses. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The NIH Agreement will terminate upon the last expiration of the patent rights or the Company may terminate the entirety of the agreement upon discontinuation of development or sales of licensed products and provision of written notice thereof to NIH. During the years ended December 31, 2021 and 2020, the Company paid $ 0.2 million and $ 0.1 million, respectively, in fees associated with the license, which were recorded as research and development expenses. License Agreements with University of Washington License Agreement with respect to RSV and Other Pathogens On June 29, 2018, the Company entered into an exclusive license agreement with an academic entity, University of Washington (the “UW 2018 Agreement”), for an exclusive license to covered intellectual property, a non-exclusive, worldwide license to use licensed know-how, and rights to sublicense for computationally designed nanoparticles and vaccines. The UW 2018 Agreement was amended in June 2019 and again in November 2020. The Company’s rights and obligations under the UW 2018 Agreement are subject to certain U.S. government rights, certain global access commitment rights for humanitarian purposes to BMGF, certain rights to Howard Hughes Medical Institute ("HHMI"), and certain other limited rights retained by University of Washington ("UW"). The Company issued 192,276 shares of common stock on August 1, 2018 in exchange for the UW 2018 Agreement’s exclusive license. The shares issued were recorded at their estimated fair value, which is de minimis, with the related expense classified as research and development in 2018. Under the UW 2018 Agreement, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. In consideration of the rights granted to the Company under the UW 2018 Agreement, the Company is required to pay an annual maintenance fee in the mid four figures starting in 2020. Additionally, the Company is required to pay minimum annual royalties following the first year after commercial sale of each licensed product. There are milestone payments due upon the completion of certain development, regulatory, and commercial milestones for licensed products in the future. The aggregate potential milestone payments for future development, regulatory, and sales-based milestones are $ 1.4 million per indication, up to a maximum of $ 6.8 million in total milestone payments. Additionally, the Company has agreed to pay a royalty of a low single digit percentage on net sales of all licensed products. Additional royalties would be due in connection with sublicenses and milestones. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The UW 2018 Agreement will terminate when all licensed rights have been terminated and all obligations due to UW have been fulfilled, or the Company may terminate the entirety of the agreement upon written notice thereof to UW. On July 2, 2020, the Company entered into a non-exclusive license agreement with respect to specified intellectual property with options for exclusivity in North America and Europe subject to the performance of certain development milestones, with UW (the “UW 2020 Agreement”). Under the UW 2020 Agreement, the Company also received a non-exclusive, worldwide license to use specific know-how and rights to sublicense for computationally designed nanoparticles and vaccines. The UW 2020 Agreement was amended in August 2020 and subsequently in May 2021. The Company’s rights and obligations under the UW 2020 Agreement as amended are subject to certain U.S. government rights, certain global access commitment rights for humanitarian purposes to BMGF, certain rights to HHMI, and certain other limited rights retained by UW. Under the UW 2020 Agreement as amended, the Company is required to use commercially reasonable efforts to meet certain specified development, sales and regulatory milestones related to the licensed products within specified time periods. The Company has agreed to pay a royalty of a low single digit percentage on net sales of all products applicable to the license. However, the Company will not be required to pay royalties on net sales of any licensed product under the UW 2020 Agreement as amended if the Company is required to pay royalties on net sales under the UW 2018 Agreement. Additional royalties would be due in connection with sublicenses and milestones. The Company’s royalty obligations continue for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The UW 2020 Agreement as amended will terminate when all licensed rights have been terminated and all obligations due to UW have been fulfilled, or the Company may terminate the entirety of the agreement upon written notice thereof to UW. During the years ended December 31, 2021 and 2020, the Company paid $ 0.2 million and $ 0.3 million respectively, in fees associated with the 2018 and 2020 Agreements. License Agreement with Respect to Influenza In September 2021, the Company entered into a license agreement with UW ("UW Flu License Agreement"). Pursuant to the UW Flu License Agreement, UW granted the Company a non-exclusive, worldwide, royalty-bearing, sublicensable (subject to certain restrictions) license under certain UW patents to make, use, sell, offer to sell, import, and otherwise exploit any product covered by the licensed patents ("Licensed Flu Products"), for the prophylactic and/or therapeutic treatment of influenza. UW also granted the Company a non-exclusive, worldwide license to use certain know-how related to the licensed patents. The licensed patents and know-how generally relate to computationally designed nanoparticles and vaccines based upon such designs, and relate to the Company's proprietary two-component virus-like-particle technology and nanoparticle-based influenza virus vaccines. As of March 2022, the UW Flu License Agreement is applicable to the Company's preclinical influenza program. The United States federal government and HHMI have similar rights under the UW Flu License Agreement and the UW License Agreement described above in “License Agreement with respect to RSV and Other Pathogens". The Company is obligated to use commercially reasonable efforts to commercialize Licensed Flu Products, and to initiate a clinical trial with respect to such Licensed Flu Products by a specified date in 2025. If the Company is unable to initiate a clinical trial by the specified date and cannot agree with UW to modify such obligation or do not cure by meeting such obligation, then UW may terminate the UW Flu License Agreement. Under the UW Flu License Agreement, the Company paid UW a one-time upfront license fee, and after September 2023 and for the remainder of the term of the UW Flu License Agreement, the Company is required to pay tiered minimum annual fees ranging from the mid four figures to the mid five figures, with such fees creditable against royalty payments. The Company is required to pay UW up to an aggregate of $ 350 thousand for payments related to development milestones and up to an aggregate of $ 6 million for payments related to commercial milestones based upon reaching certain cumulative net sales thresholds for all Licensed Flu Products. The Company is also required to pay UW a fixed low single digit percentage royalty on net sales of Licensed Flu Products by us and our sublicensees, subject to certain reductions if the Company is required to pay for third-party intellectual property rights in order to commercialize the Licensed Flu Products. The Company is not obligated to pay duplicate royalties on net sales of any Licensed Flu Products if the Company is already required to pay a royalty on such net sales under the UW License Agreement or the UW Option and License Agreement. The UW Flu License Agreement will remain in effect until all licensed patent rights have terminated and all obligations due to UW have been fulfilled. The last-to-expire licensed patent, if issued, is expected to expire in 2041 , subject to any adjustment or extension of patent term that may be available. UW can terminate the UW Flu License Agreement if the Company breaches or fails to perform one of the material duties under the UW Flu License Agreement and are unable to remedy the default within an agreed upon time period that can be extended by UW. The Company can terminate the UW Flu License Agreement at will with prior written notice to UW. The Company can also terminate certain of its licensed rights through an amendment to the UW Flu License Agreement. During year ended December 31, 2021, the Company paid $ 0.1 million in fees associated with the UW Flu License Agreement. License Agreement with the University of Texas In June 2021, the Company entered into an exclusive patent license agreement with an academic entity, the University of Texas at Austin (the “UT Agreement”). Under the UT Agreement, the Company obtained an exclusive, worldwide, royalty-bearing, sublicensable license under certain patent rights, to use licensed know-how for prevention, cure, amelioration or treatment of respiratory disease caused by metapneumovirus infection in all vaccine fields, excluding mRNA-based vaccines. The Company is obligated to pay aggregate potential milestone payments of up to $ 0.8 million with respect to future development and regulatory based milestones, and up to $ 3.8 million with respect to future sales milestones following commercialization for each licensed product for so long as licensed patent rights exist and have not expired, been revoked, lapsed, or held unenforceable. The UT Agreement will terminate upon the last expiration of the patent rights or the Company may terminate the entirety of the agreement upon written notice thereof to the University of Texas at Austin. During year ended December 31, 2021, the Company paid a negligible amount in fees associated with the UT Agreement.

Convertible Promissory Note

Convertible Promissory Note	12 Months Ended
	Dec. 31, 2021
Temporary Equity Disclosure [Abstract]
Convertible Promissory Note	7. Convertible Promissory Note In August 2020, the Company issued a $ 6.5 million convertible promissory note (“Convertible Promissory Note”). The Convertible Promissory Note accrued interest at a rate of 6 % a year with maturity date two years from issuance. The Convertible Promissory Note could be converted or redeemed as follows (i) automatically converted in a qualified Series B financing transaction from which the Company would receive total gross proceeds of not less than $ 5.0 million at a conversion price equal to 85 % of the per share price paid by investors for such securities, (ii) automatically converted upon initial public offering at a conversion price equal to 85% of the per share price off common stock in the initial public offering, (iii) optionally converted into Series A-3 preferred stock if a change in control, initial public offering, or qualified Series B financing had not occurred prior to the maturity date at a price equal to an amount determined by dividing $ 140 million by the fully diluted capitalization of the Company at the time of conversion, or (iv) repaid upon a change in control for an amount equal to the issue price plus accrued and unpaid interest or an amount as would have been payable if the noteholders had optionally converted into shares of Series A-3 preferred stock. The Convertible Promissory Note was converted in March 2021 in connection with the Series B financing. The Convertible Promissory Note is accounted for in accordance with ASC 470-20, Debt with Conversion and Other Options (“ASC 470-20”) and ASC 815-15, Derivatives and Hedging - Embedded Derivatives (“ASC 815-15”). Under ASC 815-15, an feature is required to be bifurcated if all three conditions are met: (1) economic characteristics and risks of the embedded derivative are not clearly and closely related to the economic characteristics and risks of the host contract, (2) the hybrid instrument is not remeasured at fair value under otherwise applicable GAAP with changes in fair value reported in earnings as they occur, and (3) a separate instrument which the same terms as the embedded derivative would be considered a derivative instrument subject to derivative accounting (the initial net investment for the hybrid instrument should not be considered to be the initial net investment for the embedded derivative. The Company bifurcated certain features that were required to be accounted separately for as a single embedded derivative. The initial fair value of this derivative of $ 1.8 million was recorded as a liability, and as a reduction to the carrying value of the Convertible Promissory Note. The Company also incurred approximately $ 36,000 of issuance costs related to the Convertible Promissory Note, which were also recorded as a reduction to the Convertible Promissory Note on the balance sheet. The debt discount comprised of the initial fair value of the derivative liability and the issuance costs is amortized using the effective interest method over the two-year contractual term of the Convertible Promissory Note and presented as a direct reduction of the debt liability. The debt discount was being amortized at an effective interest rate of 23.8 %. Total Convertible Promissory Note consisted of the following (in thousands): December 31, 2020 Principal amount $ 6,500 Discount related to the derivative liability and issuance costs ( 1,553 ) Net carrying amount of Convertible Promissory Note $ 4,947 Interest expense incurred in connection with the Convertible Promissory Note consisted of the following year ended December 31 (in thousands): December 31, 2021 2020 Coupon interest at 6% $ 86 $ 143 Accretion of discount and amortization of issuance costs 177 274 Total interest expense on Convertible Promissory Note $ 263 $ 417 On March 19, 2021, in connection with the closing of the Series B convertible preferred stock financing, the Convertible Promissory Note (including accrued interest) and derivative liability converted into 2,805,850 shares of Series B-2 convertible preferred stock at an issuance price of $ 2.39846 per share. As a result of the conversion, the Company recorded a loss on extinguishment of convertible promissory notes of $ 0.8 million in other expense in the statements of operations and comprehensive loss for the year ended December 31, 2021 which included the unamortized debt issuance costs.

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2021
Stockholders Equity Note [Abstract]
Convertible Preferred Stock and Stockholders' Equity (Deficit)	8. Convertible Preferred Stock and Stockholders’ Equity (Deficit) Convertible Preferred Stock Prior to its conversion into common stock in connection with the Company’s IPO in August 2021, the Company’s convertible preferred stock was classified as temporary equity on the Company’s balance sheets in accordance with authoritative guidance. Convertible preferred stock authorized and issued and its principal terms as of December 31, 2020 consisted of the following ($ amounts in thousands): Share Shares Issued Shares of Aggregate Carrying Series A-1 49,089,955 27,249,085 6,557,031 $ 26,200 $ 25,912 Series A-2 4,949,794 4,949,794 1,191,082 3,807 4,150 Total 54,039,749 32,198,879 7,748,113 $ 30,007 $ 30,062 In February 2021, the Company triggered a milestone closing associated with its Series A-1 convertible preferred stock resulting in the issuance of 21,944,874 shares. In March 2021, before the Company effected a 1-for-4.1557 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of the Company’s convertible preferred stock in July 2021, the Company entered into a convertible preferred stock purchase agreement for the issuance of 35,764,462 shares of Series B convertible preferred stock, $ 0.0001 par value per share, of which 32,958,612 shares of Series B-1 and 2,805,850 shares of Series B-2 were issued. The Series B convertible preferred stock financing resulted in net cash proceeds of $ 92.7 million, net of $ 0.35 million in issuance costs from the sale of 32,958,612 shares of Series B-1 convertible preferred stock at a price of $ 2.82172 per share. In addition, the Convertible Promissory Note of $ 6.5 million that the Company issued in August 2020, including accrued interest as of the date of conversion of $ 0.2 million, was converted into 2,805,850 shares of Series B-2 convertible preferred stock on March 19, 2021 at 85 % of the offering’s share price. In connection with the Company’s IPO in August 2021, all outstanding shares of the convertible preferred stock converted into 21,634,898 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of convertible preferred stock outstanding as of the closing of the IPO. In addition, on August 2, 2021, the Company amended and restated its certificate of incorporation to authorize 500,000,000 shares of common stock and 50,000,000 shares of preferred stock, which shares of preferred stock are currently undesignated. The Company does no t have any outstanding preferred stock as of December 31, 2021. Equity Incentive Plans In 2017, the Company established a stock option plan (the “2017 Plan”) under which incentives may be granted to officers, employees, directors, consultants and advisors. Awards under the 2017 Plan may consist of restricted stock and incentive and non-qualified stock options to purchase shares of common stock of the Company. During 2021, the Company’s stockholders approved the 2021 Incentive Plan (the “2021 Plan”), which became effective in July 2021. The 2021 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock, dividend equivalents, restricted stock units and other stock or cash-based awards. The number of shares of the Company’s common stock initially reserved for issuance under the 2021 Plan is 4,600,000 shares; plus the shares of common stock remaining available for issuance under the 2017 Plan as of the effective date of the 2021 Plan, as well as any shares subject to outstanding awards under the 2017 Plan as of the effective date of the 2021 Plan that become available for issuance under the 2021 Plan thereafter in accordance with its terms. The number of shares initially available for issuance increases annually on January 1 of each calendar year beginning in 2022 and ending in and including 2031, equal to the lesser of (A) 5 % of the shares outstanding on the final day of the immediately preceding calendar year and (B) a smaller number of shares as determined by our board of directors. The reserve for the 2021 Plan increased by 5 %, or 1,971,455 shares, effective January 1, 2022. No more than 50,000,000 shares of common stock may be issued under the 2021 Plan upon the exercise of incentive stock options. The 2021 Plan is administered by the Board of Directors of the Company or a committee appointed by the Board of Directors, which determines the types of awards to be granted, including the number of shares subject to the awards, the exercise price and the vesting schedule. All existing grants are subject to a time-based vesting period which will generally be four years . Certain option and share awards provide for accelerated vesting if there is a change in control or if other contractually specified contingencies are met. The term of stock options granted under the 2021 Plan cannot exceed ten years (or five years in the case of incentive stock options granted to certain significant stockholders). Options shall not have an exercise price less than 100 % of the fair market value of the Company’s common stock on the grant date (or 110 % in the case of incentive stock options granted to certain significant stockholders), except with respect to certain substitute awards granted in connection with a corporate transaction. A summary of the status of the options issued under the Company’s equity incentive plans as of December 31, 2021, and information with respect to the changes in options outstanding is as follows: Option Pool Options Weighted Average Exercise Weighted Average Remaining Aggregate Balance at December 31, 2020 541,411 641,427 $ 0.84 9.02 $ — Authorized increase in plan shares 22,634,965 — — — — Granted ( 6,177,633 ) 6,177,633 8.52 — — Exercised (including early) — ( 227,333 ) 0.84 — $ 1,012,104 Balance at December 31, 2021 16,998,743 6,591,727 $ 8.04 9.26 $ 101,725,631 Vested and expected to vest as of 6,591,727 $ 8.04 9.26 $ 101,725,631 Vested and exercisable at 826,952 $ 5.71 9.05 $ 14,199,668 Exercisable options in the table above reflect the number of options vested as of the date reported. The 2021 Plan permits early exercises of options. Cash received for early exercise of unvested options is recognized as an other noncurrent liability in the accompanying balance sheet and totaled $ 0.2 million at December 31, 2021. The aggregate intrinsic value in the table above is calculated as the difference between the exercise price of the underlying options and the fair value of the Company’s common stock for all options that were in-the-money as of December 31, 2021. During the year ended December 31, 2021, the Company granted 6,177,633 options, with a grant date fair value of $ 48.3 million. During the year ended December 31, 2020, the Company granted 271,405 options, with a grant date fair value of $ 0.3 million. The weighted-average grant date fair value of employee option grants during the years ended December 31, 2021 and 2020 were $ 8.52 and $ 1.06 per share, respectively. During the year ended December 31, 2021, the Company granted 388,500 restricted stock unit ("RSU") awards, with a grant date fair value of $ 10.1 million. The weighted-average grant date fair value of RSU awards during the year ended December 31, 2021 was $ 25.96 . All RSU awards granted during the year ended December 31, 2021 were nonvested as of December 31, 2021. There were no RSU awards granted during the year ended December 31, 2020. Common Stock As of December 31, 2021 and 2020, of the 500,000,000 and 78,000,000 authorized shares of common stock, respectively, 39,429,103 and 3,596,936 shares were issued, respectively, and 39,175,279 and 2,639,026 shares were outstanding, respectively. As of December 31, 2021 and 2020, the Company had 2,347,629 shares of restricted common stock that had been issued to members of management at a price of $ 0.004 per share, and 269,694 shares of common stock that had been issued to a university in connection with obtaining a licensing agreement. At December 31, 2021 and 2020, 2,347,629 and 1,995,314 shares of the restricted common stock have vested, respectively. At December 31, 2021, no shares were subject to vesting conditions. Common stock reserved for future issuance consisted of the following: As of December 31, 2021 Common stock options and restricted stock units granted and outstanding 6,980,227 Shares available for issuance under the equity incentive plans 8,187,715 Shares available for issuance under the 2021 Employee Stock Purchase Plan 1,183,394 Total common stock reserved for issuance 16,351,336 Stock-Based Compensation Expense Stock-based compensation expense for all equity awards and the 2021 Employee Stock Purchase Plan, has been reported in the statements of operations and comprehensive loss as follows (in thousands): Year Ended 2021 2020 Research and development $ 2,710 $ 137 General and administrative 26,321 120 Total $ 29,031 $ 257 The Company recognizes compensation expense for options and RSU awards granted to employees and the board of directors based on their grant date fair value. The compensation expense is recognized over the vesting period of 4 years on a straight-line basis. The fair value of each stock option granted was determined using the Black-Scholes option pricing model. The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee and nonemployee stock option grants issued during years ended were as follows: Year Ended 2021 2020 Risk-free rate of interest 0.63 %- 1.34 % 0.31 %- 1.40 % Expected term (years) 5.77 - 6.08 years 5.90 - 6.08 years Expected stock price volatility 84.2 % - 90.9 % 80.2 % - 86.4 % Dividend yield 0 % 0 % As of December 31, 2021, the unrecognized compensation cost related to outstanding stock options and RSU awards was $ 39.4 million and $ 9.0 million, respectively and is expected to be recognized as expense over a weighted-average period of approximately 3.41 years. On August 4, 2021, as a result of the death of Tadataka (Tachi) Yamada, M.D., the Company's former Chairman, the Company's Board of Directors decided to accelerate the vesting of all of Dr. Yamada's previously unvested stock options as of the date of his death. The Company accelerated the vesting of 611,639 stock options, with exercise prices ranging from $ 0.83 to $ 5.90 per share, resulting in incremental non-cash, stock-based compensation of $ 21.0 million being recorded in 2021 as general and administrative expense. Employee Stock Purchase Plan During 2021, the Company’s stockholders approved the 2021 Employee Stock Purchase Plan (the “ESPP”), which became effective in July 2021. The ESPP permits eligible employees who elect to participate in an offering under the ESPP to have up to 15% of their eligible earnings withheld, subject to certain limitations, to purchase shares of common stock pursuant to the ESPP. The price of common stock purchased under the ESPP is equal to 85% of the lower of the fair market value of the common stock at the commencement date of each offering period or the relevant date of purchase. The number of shares of common stock initially reserved for issuance under the ESPP is 400,000 shares. The number of shares of common stock reserved for issuance under the ESPP increases on January 1, 2022 and each January 1 thereafter through January 1, 2031, in an amount equal to the lower of (1) 1 % of the aggregate number of shares of common stock of the Company outstanding on the final day of the immediately preceding calendar year and (2) such smaller number of shares of common stock as determined by the Board, provided that no more than 15,000,000 shares of our common stock may be issued under the ESPP. The reserve for the ESPP increased by 1 % or 394,291 shares, on January 1, 2022. As of December 31, 2021, 16,606 shares have been purchased by employees under the ESPP. Stock-based compensation expense related to the ESPP for the year ended December 31, 2021 was $ 0.1 million.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes The reconciliations of the U.S. statutory federal income tax rates to the Company's effective tax rates were as follows: Year Ended 2021 2020 U.S. federal statutory income tax rate 21.0 % 21.0 % Adjustments for the tax effects of: State income taxes, net of federal tax 1.0 0.6 Other permanent differences ( 0.4 ) ( 0.3 ) Research and development tax credits 3.1 3.8 Research and development credit permanent adjustment ( 0.6 ) ( 1.3 ) Stock-based compensation ( 1.6 ) ( 0.3 ) Uncertain tax positions ( 0.8 ) ( 1.0 ) Change in valuation allowance ( 21.7 ) ( 22.5 ) Effective income tax rate — % — % Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The significant components of our deferred tax assets and liabilities are as follows (in thousands): As of December 31, 2021 2020 Deferred tax assets Net operating loss carryforwards $ 12,623 $ 4,549 Research and development credits 2,349 790 Deferred revenue 126 515 Stock-based compensation 5,192 — Other 533 226 Total deferred tax assets 20,823 6,080 Less: deferred tax liabilities ( 280 ) ( 3 ) Less: valuation allowance ( 20,543 ) ( 6,077 ) Net deferred tax assets $ — $ — Due to the uncertainty surrounding the realization of deductible tax attributes in future tax returns, the Company has recorded a valuation allowance against its net deferred tax assets as of December 31, 2021 and 2020. Utilization of the net operating loss carryforwards is dependent on future taxable income. As such, realization is not assured, and a valuation allowance has been established. The valuation allowance for deferred tax assets was approximately $ 20.5 million as of December 31, 2021, an increase of $ 14.4 million during the year ended December 31, 2021. The Company has total net operating loss carryforwards for U.S. federal income tax and state purposes of approximately $ 57.0 million and $ 11.9 million, respectively, as of December 31, 2021 which begin to expire in 2037 and 2035 , respectively. Federal net operating losses generated after January 1, 2018 will be carried forward indefinitely. The Company has federal research and development tax credit carryforwards of approximately $ 3.0 million as of December 31, 2021, which begin to expire in 2037 . Additionally, the Company has state research and development credit carryforwards of approximately $ 168,000 as of December 31, 2021, which carryforward indefinitely. The operating loss carryforwards and research and development tax credits may be limited due to a change in control in the Company’s ownership as defined by the Internal Revenue Code Sections 382 and 383. The Company files federal and state income tax returns. The Company is not currently under examination but is open to audit by the I.R.S. and state tax authorities for tax years beginning in 2017. The resolutions of any examinations are not expected to be material to these financial statements. As of December 31, 2021, there are no penalties or accrued interest recorded in the financial statements. A reconciliation of the beginning and ending amount of unrecognized tax benefits for uncertain tax positions were as follows (in thousands): Year Ended December 31, 2021 2020 Unrecognized tax benefits, beginning of year $ 263 $ 84 Additions based on tax positions relating to current year 495 242 Additions based on tax positions relating to prior year — — Reductions for positions of prior years — ( 63 ) Unrecognized tax benefits, end of year $ 758 $ 263 The Company does not believe it is reasonably possible that its unrecognized tax benefits will change materially in the next twelve months.

Employee Savings Plan

Employee Savings Plan	12 Months Ended
	Dec. 31, 2021
Postemployment Benefits [Abstract]
Employee Saving Plan	10. Employee Savings Plan The Company has a defined contribution 401(k) savings plan for those employees who meet minimum eligibility requirements. Under the terms of the plan, eligible employees may contribute up to 90 % of their annual compensation to the plan, subject to Internal Revenue Service limitations. The Company may also, at its sole discretion, make contributions to the plan. The Company did no t make any contributions to the plan during 2021 or 2020.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) promulgated by the Financial Accounting Standards Board (“FASB”).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported balances of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates are used for, but not limited to, stock-based compensation, derivative liability, the timing of research and development accruals, and income taxes. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. The full extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including expenses, clinical trials and research and development costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, as well as the economic impact on local, regional, national and international markets. The Company has considered potential impacts arising from the COVID-19 pandemic and is not presently aware of any events or circumstances that would require the Company to update its estimates, judgments or revise the carrying value of its assets or liabilities.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments which potentially subject the Company to significant concentration of credit risk consist of cash and restricted cash. The Company is exposed to credit risk from its deposits of cash in excess of amounts insured by the Federal Deposit Insurance Corporation. The Company maintains an Insured Cash Sweep account where balances are maintained in interest bearing demand accounts. The Company has not experienced any losses on its deposits of cash since inception, and management believes that the Company is not exposed to significant credit risk due to the financial positions of the respective depository institutions in which those deposits are held
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. The Company’s comprehensive loss was the same as its reported net loss for all periods presented.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The accounting guidance defines fair value, establishes a consistent framework for measuring fair value, and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The carrying amounts of all cash, restricted cash, prepaid expenses and other assets, accounts payable, and accrued and other current liabilities are considered to be representative of their respective fair values due to their short maturities. The carrying values of the derivative liability of $ 1.6 million (level 3 fair value) and the convertible promissory note of $ 4.9 million in the accompanying balance sheet at December 31, 2020 approximate fair value because they collectively converted into 2,805,850 shares of Series B convertible preferred stock in March 2021.
Cash	Cash Cash represents funds in the Company’s operating bank account. The Company has no cash equivalents.
Restricted Cash	Restricted Cash The Company’s restricted cash includes payments received under the Grant Agreement (as defined in Note 4) with the Bill & Melinda Gates Foundation (“BMGF”) under which the Company was awarded a grant of up to $ 10.0 million. The Company will utilize the Grant Agreement funds as it incurs expenses for services performed under the agreement. Restricted cash also includes cash collateral supporting the standby letter of credit discussed in "Leases" below.
Property and equipment, net	Property and equipment, net Property and equipment, net is stated at cost, net of accumulated depreciation and is depreciated using the straight-line method over the estimated useful lives of the assets (generally two to five years ).
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company regularly reviews the carrying value and estimated lives of its long-lived assets, including property and equipment to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. Should an impairment exist, the impairment loss would be measured based on the excess over the carrying amount of the asset’s fair value. The Company has no t recognized any impairment losses from inception through December 31, 2021.
Derivative Liability, Convertible Notes Discount and Amortization	Derivative Liability, Convertible Notes Discount and Amortization The Company’s convertible note (see Note 7) had conversion and redemption features that met the definition of an embedded derivative and were therefore subject to bifurcation and derivative accounting. The initial recognition of the fair value of the derivative resulted in a discount to the convertible note, with a corresponding derivative liability. The discount to the convertible note was amortized using the effective interest method. The amortization of the discount is included in interest and other income (expense) in the statements of operations and comprehensive loss. The derivative liability related to these features was recorded at estimated fair value and remeasured on a recurring basis. Any changes in fair value were reflected as change in fair value of derivative liability in the statements of operations and comprehensive loss at each reporting date while such instruments were outstanding. The derivative liability was settled in March 2021 upon conversion of the underlying convertible note into Series B convertible preferred stock, resulting in a loss on extinguishment of convertible promissory note
Leases	Leases At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use asset upon commencement of the lease using the implicit rate or a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. The Company additionally evaluates leases at their inception to determine if they are to be accounted for as an operating lease or a finance lease. A lease is accounted for as a finance lease if it meets one of the following five criteria: the lease has a purchase option that is reasonably certain of being exercised, the present value of the future cash flows is substantially all of the fair market value of the underlying asset, the lease term is for a significant portion of the remaining economic life of the underlying asset, the title to the underlying asset transfers at the end of the lease term, or if the underlying asset is of such a specialized nature that it is expected to have no alternative uses to the lessor at the end of the term. Leases that do not meet the finance lease criteria are accounted for as an operating lease. Operating lease assets represent a right to use an underlying asset for the lease term and operating lease liabilities represent an obligation to make lease payments arising from the lease. Operating lease liabilities with a term greater than one year and their corresponding right-of-use assets are recognized on the balance sheet at the commencement date of the lease based on the present value of lease payments over the expected lease term. Certain adjustments to the right-of-use asset may be required for items such as initial direct costs paid or incentives received. As the Company’s leases do not typically provide an implicit rate, the Company utilizes the appropriate incremental borrowing rate, determined as the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and in a similar economic environment. Lease cost is recognized on a straight-line basis over the lease term and variable lease payments are recognized as operating expenses in the period in which the obligation for those payments is incurred. Variable lease payments primarily include common area maintenance, utilities, real estate taxes, insurance, and other operating costs that are passed on from the lessor in proportion to the space leased by the Company. The Company has elected the practical expedient to not separate lease and non-lease components. In January 2020, and amended in March 2020, the Company entered into a lab license agreement for office and lab space in Seattle, Washington. The lab license agreement is twelve months and provides for renewal options. The monthly base rent is approximately $ 16,000 . The lab license agreement is considered short-term and therefore, no right-of-use asset or lease liability has been recorded. In December 2021, the Company entered into a lease agreement for corporate office and lab space in Seattle, Washington. The Company took possession of certain leased space at various dates in January 2022 and March 2022. The lease agreement is five years and 3 months and provides for a one-time option to extend for a period of five additional years. The monthly base rent will be $ 0.2 million for the first year and will increase by 3.0 % per year over the initial term. In addition, the Company is obligated to pay for common area maintenance and other costs. Under the terms of the lease agreement, the Company is required to maintain a standby letter of credit of $ 1.1 million at the execution of the lease agreement, reduced to $ 0.9 million at the first anniversary, and further reduced to $ 0.7 million at the second anniversary of the lease. As of December 31, 2021, the Company had not taken control of the space and the lease term had not commenced; therefore, no right-of-use asset or lease liability has been recognized.
Grant Revenue	Grant Revenue The Company’s revenue consists of revenue under its Grant Agreement with BMGF (see Note 4). The Company is reimbursed for certain costs that support development activities, including the Company’s clinical trial notification (“CTN”) preparations for and planned first-in-human Phase 1/2 clinical trial of COVID-19 RBD VLP vaccine in Australia. The Company’s Grant Agreement does not provide a direct economic benefit to BMGF. Rather, the Company entered into an agreement with BMGF to make a certain amount of any resulting vaccine available and accessible at affordable pricing to people in certain low- and middle-income countries. The Company assessed this cost reimbursement agreement to determine if the agreement should be accounted for as an exchange transaction or a contribution. Such an agreement is accounted for as a contribution if the resource provider does not receive commensurate value in return for the assets transferred. Contributions are recognized as grant revenue when all donor-imposed conditions have been met. As BMGF ultimately determines if milestones under the agreement are met and if funding should continue, there may be a difference in timing between when research and development expenses are incurred and when grant revenue is recognized.
Accrued Research and Development Expense	Accrued Research and Development Expense The Company is required to estimate its obligation for expenses incurred under contracts with vendors, consultants, and contract research organizations, in connection with conducting research and development activities. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company reflects research and development expenses in its financial statements by recognizing those expenses in the periods in which services and efforts are expended. The Company accounts for these expenses according to the progress of the preclinical study or clinical trial, as measured by the timing of various aspects of the study, trial or related activities. The Company determines accrual estimates through review of the underlying contracts along with preparation of financial models taking into account discussions with research and other key personnel and third-party service providers as to the progress of studies or trials, or other services being conducted. To date, the Company has had no material differences between its estimates of such expenses and the amounts actually incurred. During the course of a study or trial, the Company adjusts its expense recognition if actual results differ from its estimate. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed or services are performed.
Research and Development	Research and Development Research and development costs are expensed as incurred and consist primarily of external and internal costs related to the development of vaccine candidates, including salaries and benefits, stock-based compensation, facilities and depreciation, contracted research, consulting arrangements, and other expenses incurred to sustain the Company’s research and development programs
Interest Income	Interest Income Interest income consists of interest income earned on interest bearing demand accounts.
Liability For Early Exercise Of Stock Options	Liability for Early Exercise of Stock Options Certain individuals were granted the ability to early exercise their stock options. The shares of common stock issued from the early exercise of unvested stock options are restricted and continue to vest in accordance with the original vesting schedule. The Company has the option to repurchase any unvested shares at the original purchase price upon any voluntary or involuntary termination. The shares purchased by the employees and non-employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be outstanding until those shares vest. The cash received in exchange for exercised and unvested shares related to stock options granted is recorded as a liability for the early exercise of stock options on the accompanying balance sheets and will be reclassified as common stock and additional paid-in capital as the shares vest. Unvested shares issued under early exercise provisions subject to repurchase by the Company totaled 253,824 and 488,226 shares as of December 31, 2021 and 2020, respectively. As of December 31, 2021 and 2020, the Company had $ 0.2 million and $ 0.2 million respectively, of amounts related to shares issued with repurchase rights classified as other noncurrent liabilities in the accompanying balance sheets.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee, officer, director and non-employee stock option grants, estimated in accordance with the applicable accounting guidance, recognized on a straight-line basis over the vesting period. The vesting period generally approximates the expected service period of the awards. The Company recognizes forfeitures as they occur. The Black-Scholes option pricing model uses inputs which are assumptions that generally require judgment. These assumptions include: ▪ Fair Value of Common Stock . Prior to the Company’s IPO, the grant date fair market value of the shares of common stock underlying stock options was historically determined by the Company’s board of directors. Because there was no public market for the Company’s common stock, the board of directors exercised reasonable judgment and considered a number of objective and subjective factors to determine the best estimate of the fair market value, which included contemporaneous valuations performed by an independent third-party, the Company’s results of operations and financial position, including its levels of available capital resources, its stage of development and material risks related to the Company’s business, progress of the Company’s research and development activities, the Company’s business conditions and projections, the lack of marketability of the Company’s common stock and preferred stock as a private company, the prices at which the Company sold shares of its convertible preferred stock to outside investors in arms-length transactions, the rights, preferences and privileges of the Company’s redeemable convertible preferred stock relative to those of its common stock, the analysis of initial public offerings and the market performance of similar companies in the biopharmaceutical industry, the likelihood of achieving a liquidity event for the Company’s securityholders, such as an initial public offering or a sale of the Company, given prevailing market conditions, the hiring of key personnel and the experience of management, trends and developments in the Company’s industry, and external market conditions affecting the life sciences and biopharmaceutical industry sectors. Subsequent to the Company’s IPO, the grant date fair value of the Company’s common stock is determined based on its closing price. ▪ Expected Term . The expected term represents the period that the options granted are expected to be outstanding. The expected term of stock options issued is determined using the simplified method (based on the average of the vesting term and the original contractual term) as the Company has concluded that its stock option exercise history does not provide a reasonable basis upon which to estimate expected term. ▪ Expected Volatility . Given the Company’s limited historical stock price volatility data, the Company derived the expected volatility from the average historical volatilities over a period approximately equal to the expected term of comparable publicly traded companies within the Company’s peer group that were deemed to be representative of future stock price trends as the Company has limited trading history for its common stock. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. ▪ Risk-Free Interest Rate . The risk-free interest rate is based on the U.S. Treasury zero-coupon issues in effect at the time of grant for periods corresponding with the expected term of the options. ▪ Expected Dividend Yield . The Company never paid dividends on its common stock and do not anticipate paying any dividends in the foreseeable future. Therefore, the Company used an expected dividend yield of zero. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date.
Commitments and Contingencies	Commitments and Contingencies The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has been incurred, and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount the Company accrues the minimum amount in the range. In the event the Company becomes subject to claims or suits arising in the ordinary course of business, the Company would accrue a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. The Company has not recorded any such liabilities at either December 31, 2021 or 2020.
Income Tax	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. As of December 31, 2021 and 2020, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes may result in a change in the estimated annual effective tax rate. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. As of December 31, 2021, the Company had no accrued interest or penalties.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and common stock equivalents outstanding for the period. Common stock equivalents are only included when their effect is dilutive. The Company’s potentially dilutive securities include outstanding stock options under the Company’s equity incentive plan and have been excluded from the computation of diluted net loss per share as they would be anti-dilutive to the net loss per share. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position. The following tables summarize the computation of the basic and diluted net loss per share (in thousands, except share and per share data): Year Ended 2021 2020 Numerator: Net loss $ ( 66,971 ) $ ( 18,854 ) Denominator: Weighted-average common shares outstanding, basic and diluted 18,587,782 3,517,671 Less: Weighted-average unvested common stock ( 621,888 ) ( 1,272,448 ) Weighted-average shares used to compute net loss per share, basic and 17,965,894 2,245,223 Net loss per share, basic and diluted $ ( 3.73 ) $ ( 8.40 ) The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive. Year Ended 2021 2020 Series A convertible preferred stock — 32,198,879 Common stock options 6,591,727 641,427 ESPP shares 16,606 — Unvested common stock 253,824 957,711 Total 6,862,157 33,798,017
Segments	Segments The Company has determined that it operates and manages one operating segment, which is the business of researching and developing vaccines against infectious diseases. The Company’s chief operating decision maker, its chief executive officer, reviews financial information on an aggregate basis for the purpose of allocating resources. All assets of the Company are located in the United States.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, Income Taxes—Simplifying the Accounting for Income Taxes (“ASU 2019-12”). The new guidance simplifies the accounting for income taxes by removing several exceptions in the current standard and adding guidance to reduce complexity in certain areas, such as requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. The new standard is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022 for all non-public entities, with early adoption permitted, and is effective for fiscal years beginning after December 15, 2020, including interim periods within those annual periods for public entities. Early adoption is permitted. The Company adopted ASU 2019-12 on January 1, 2021 and the standard did not have a material impact on its financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Computation of Basic and Diluted Net Loss Per Share	The following tables summarize the computation of the basic and diluted net loss per share (in thousands, except share and per share data): Year Ended 2021 2020 Numerator: Net loss $ ( 66,971 ) $ ( 18,854 ) Denominator: Weighted-average common shares outstanding, basic and diluted 18,587,782 3,517,671 Less: Weighted-average unvested common stock ( 621,888 ) ( 1,272,448 ) Weighted-average shares used to compute net loss per share, basic and 17,965,894 2,245,223 Net loss per share, basic and diluted $ ( 3.73 ) $ ( 8.40 )
Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share	The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive. Year Ended 2021 2020 Series A convertible preferred stock — 32,198,879 Common stock options 6,591,727 641,427 ESPP shares 16,606 — Unvested common stock 253,824 957,711 Total 6,862,157 33,798,017

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value, Liabilities Measured on Recurring Basis	The following table summarizes financial liabilities that the Company measured at fair value on a recurring basis, classified in accordance with the fair value hierarchy (in thousands): Fair Value Measurements at Report Date Using Total (Level 1) (Level 2) (Level 3) As of December 31, 2020 Embedded derivative liability $ ( 1,604 ) $ — $ — $ ( 1,604 )
Fair Value Measurement Inputs and Valuation Techniques	The following table summarizes information about the significant unobservable inputs used in the fair value measurements for the derivative liability: March 19, 2021 December 31, 2020 August 20, 2020 Probability of financing 100 % 90 % 90 % Probability of dissolution — 10 % 10 % Time to liquidity (years) — 0.50 - 1.00 0.83 - 1.33 Discount rate 7.6 % 8.3 % 11.9 %
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following table provides a reconciliation of the fair value of the derivative liability using Level 3 significant unobservable inputs (in thousands): Derivative Liability Fair value at December 31, 2019 $ — Fair value of derivative liability at issuance of convertible promissory note ( 1,791 ) Change in fair value of derivative liability (Note 7) 187 Fair value at December 31, 2020 ( 1,604 ) Change in fair value of embedded derivative liability ( 205 ) Reclassification of derivative liability into convertible preferred stock resulting from conversion of convertible promissory note 1,809 Fair value at December 31, 2021 $ —

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Schedule of property and equipment	Property and equipment, net, consists of the following (in thousands): As of December 31, 2021 2020 Laboratory equipment $ 856 $ 11 Construction in progress 303 — Property and equipment, cost 1,159 11 Accumulated depreciation ( 83 ) ( 1 ) Property and equipment, net $ 1,076 $ 10
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consist of the following (in thousands): As of December 31, 2021 2020 Taxes payable $ — $ 91 Accrued paid time off 342 137 Accrued bonus 2,216 696 Other accrued liabilities 1,977 608 Accrued 401k 156 — ESPP liability 66 — Total accrued and other current liabilities $ 4,757 $ 1,532

Convertible Promissory Note (Ta

Convertible Promissory Note (Tables)	12 Months Ended
	Dec. 31, 2021
Convertible Promissory Note [Abstract]
Summary of Convertible Promissory Note	Total Convertible Promissory Note consisted of the following (in thousands): December 31, 2020 Principal amount $ 6,500 Discount related to the derivative liability and issuance costs ( 1,553 ) Net carrying amount of Convertible Promissory Note $ 4,947
Summary Of Interest Expense Of Convertible Promissory Note	Interest expense incurred in connection with the Convertible Promissory Note consisted of the following year ended December 31 (in thousands): December 31, 2021 2020 Coupon interest at 6% $ 86 $ 143 Accretion of discount and amortization of issuance costs 177 274 Total interest expense on Convertible Promissory Note $ 263 $ 417

Convertible Preferred Stock a_2

Convertible Preferred Stock and Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders Equity Note [Abstract]
Schedule of Convertible Preferred Stock	Convertible preferred stock authorized and issued and its principal terms as of December 31, 2020 consisted of the following ($ amounts in thousands): Share Shares Issued Shares of Aggregate Carrying Series A-1 49,089,955 27,249,085 6,557,031 $ 26,200 $ 25,912 Series A-2 4,949,794 4,949,794 1,191,082 3,807 4,150 Total 54,039,749 32,198,879 7,748,113 $ 30,007 $ 30,062
Summary of the Status of the Options Issued Under the Plan	A summary of the status of the options issued under the Company’s equity incentive plans as of December 31, 2021, and information with respect to the changes in options outstanding is as follows: Option Pool Options Weighted Average Exercise Weighted Average Remaining Aggregate Balance at December 31, 2020 541,411 641,427 $ 0.84 9.02 $ — Authorized increase in plan shares 22,634,965 — — — — Granted ( 6,177,633 ) 6,177,633 8.52 — — Exercised (including early) — ( 227,333 ) 0.84 — $ 1,012,104 Balance at December 31, 2021 16,998,743 6,591,727 $ 8.04 9.26 $ 101,725,631 Vested and expected to vest as of 6,591,727 $ 8.04 9.26 $ 101,725,631 Vested and exercisable at 826,952 $ 5.71 9.05 $ 14,199,668
Schedule of common stock reserved for future issuance	Common stock reserved for future issuance consisted of the following: As of December 31, 2021 Common stock options and restricted stock units granted and outstanding 6,980,227 Shares available for issuance under the equity incentive plans 8,187,715 Shares available for issuance under the 2021 Employee Stock Purchase Plan 1,183,394 Total common stock reserved for issuance 16,351,336
Schedule of Stock-based Compensation Expense for All Equity Awards	Stock-based compensation expense for all equity awards and the 2021 Employee Stock Purchase Plan, has been reported in the statements of operations and comprehensive loss as follows (in thousands): Year Ended 2021 2020 Research and development $ 2,710 $ 137 General and administrative 26,321 120 Total $ 29,031 $ 257
Summary of Assumptions Used in Black-Scholes Model	The fair value of each stock option granted was determined using the Black-Scholes option pricing model. The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee and nonemployee stock option grants issued during years ended were as follows: Year Ended 2021 2020 Risk-free rate of interest 0.63 %- 1.34 % 0.31 %- 1.40 % Expected term (years) 5.77 - 6.08 years 5.90 - 6.08 years Expected stock price volatility 84.2 % - 90.9 % 80.2 % - 86.4 % Dividend yield 0 % 0 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Reconciliation of Federal Statutory Income Tax Rate and Effective Income Tax Rate	The reconciliations of the U.S. statutory federal income tax rates to the Company's effective tax rates were as follows: Year Ended 2021 2020 U.S. federal statutory income tax rate 21.0 % 21.0 % Adjustments for the tax effects of: State income taxes, net of federal tax 1.0 0.6 Other permanent differences ( 0.4 ) ( 0.3 ) Research and development tax credits 3.1 3.8 Research and development credit permanent adjustment ( 0.6 ) ( 1.3 ) Stock-based compensation ( 1.6 ) ( 0.3 ) Uncertain tax positions ( 0.8 ) ( 1.0 ) Change in valuation allowance ( 21.7 ) ( 22.5 ) Effective income tax rate — % — %
Schedule Of Components Of Deferred Tax Assets And Liabilities	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The significant components of our deferred tax assets and liabilities are as follows (in thousands): As of December 31, 2021 2020 Deferred tax assets Net operating loss carryforwards $ 12,623 $ 4,549 Research and development credits 2,349 790 Deferred revenue 126 515 Stock-based compensation 5,192 — Other 533 226 Total deferred tax assets 20,823 6,080 Less: deferred tax liabilities ( 280 ) ( 3 ) Less: valuation allowance ( 20,543 ) ( 6,077 ) Net deferred tax assets $ — $ —
Summary of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits for uncertain tax positions were as follows (in thousands): Year Ended December 31, 2021 2020 Unrecognized tax benefits, beginning of year $ 263 $ 84 Additions based on tax positions relating to current year 495 242 Additions based on tax positions relating to prior year — — Reductions for positions of prior years — ( 63 ) Unrecognized tax benefits, end of year $ 758 $ 263 The Company does not believe it is reasonably possible that its unrecognized tax benefits will change materially in the next twelve months.

Description of Business - Addit

Description of Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Aug. 02, 2021	Mar. 31, 2021	Aug. 31, 2021	Jul. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Subsidiary Sale Of Stock [Line Items]
Stock split		1-for-4.1557		1-for-4.1557
Sale of common stock					39,429,103	3,596,936
Proceeds from initial public offering, net of offering costs					$ 190,738	$ 0
Preferred stock, shares outstanding					0	0
Accumulated Deficit					$ 94,069	$ 27,098
Cash					279,082	$ 13,114
Restricted Cash					$ 1,600
IPO [Member]
Subsidiary Sale Of Stock [Line Items]
Sale of common stock	12,133,333
Offering price per share	$ 15
Additional shares purchasable by underwriters	1,819,999
Proceeds from initial public offering, net of offering costs	$ 190,700
Preferred stock, shares outstanding	89,908,215				0
Common stock converted	21,634,898		21,634,898

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)Segmentshares	Mar. 19, 2021shares	Dec. 31, 2020USD ($)shares	Jan. 31, 2020USD ($)
Derivatives liability, carrying value	$ 1,800,000		$ 1,600,000
Convertible preferred stock issued upon conversion | shares			7,748,113
Restricted Cash	1,600,000
Impairment losses	$ 0
Number of shares subject to repurchase | shares	253,824		488,226
Liabilities with shares issued with repurchase rights	$ 200,000		$ 200,000
Accrued interest and penalties	$ 0
Number Of Reporting Units | Segment	1
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property Plant And Equipment Net		Property Plant And Equipment Net
Lab License Agreement [Member]
Monthly Base Rent	$ 16,000
Lease agreement term	12 months
Lease agreement option to extend	The lab license agreement is twelve months and provides for renewal options.
Right-of-use asset	$ 0			$ 0
Lease liability	0			$ 0
Lease Agreement [Member]
Monthly Base Rent	$ 200,000
Monthly base rent yearly increase percentage	3.00%
Lease agreement term	5 years 3 months
Lease agreement option to extend	The lease agreement is five years and 3 months and provides for a one-time option to extend for a period of five additional years.
Lease term option to extend for additional years	5 years
Minimum [Member]
Property and equipment useful lives of assets	2 years
Maximum [Member]
Property and equipment useful lives of assets	5 years
Bill And Melinda Gates Foundation
Restricted Cash	$ 10,000,000
Series B [Member]
Convertible preferred stock issued upon conversion | shares		2,805,850
Standby Letters of Credit [Member] | Lease Agreement [Member]
Standby letters of credit	1,100,000
First Anniversary [Member] | Lease Agreement [Member]
Standby letters of credit	900,000
Second Anniversary [Member] | Lease Agreement [Member]
Standby letters of credit	$ 700,000
Promissory Note [Member]
Convertible note			$ 4,900,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (66,971)	$ (18,854)
Denominator:
Weighted-average common shares outstanding, basic and diluted	18,587,782	3,517,671
Less: Weighted average unvested common stock	(621,888)	(1,272,448)
Weighted average shares used to compute net loss per share, basic and diluted	17,965,894	2,245,223
Net loss per share, basic and diluted	$ (3.73)	$ (8.40)

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common equivalent shares	6,862,157	33,798,017
ESPP Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common equivalent shares	16,606	0
Series A
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common equivalent shares	0	32,198,879
Common Stock [Member] | Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common equivalent shares	6,591,727	641,427
Unvested Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common equivalent shares	253,824	957,711

Fair value measurements - Sched

Fair value measurements - Schedule of Fair Value Liabilities Measured on Recurring Basis (Details) $ in Thousands	Dec. 31, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative liability	$ (1,604)
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative liability	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative liability	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative liability	$ (1,604)

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Mar. 19, 2021	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Convertible preferred stock issued upon conversion			7,748,113
Loss on extinguishment of convertible promissory note		$ (754,000)	$ 0
Series B2 Convertible Preferred Stock [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Promissory note and derivative liability conversion into share	2,805,850
Convertible preferred stock issued upon conversion	2,805,850
Operating Expense [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Change in fair value of embedded derivative liability		200	$ 200
Operating Expense [Member] | Series B2 Convertible Preferred Stock [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loss on extinguishment of convertible promissory note		800,000
Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities measured at fair value		0
Asset Measured at fair value		$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Significant Unobservable Inputs Used in the Fair Value Measurements for the Derivative Liability (Details)	Mar. 19, 2021	Dec. 31, 2020	Aug. 20, 2020
Measurement Input Probability Of Financing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liability	100	90	90
Measurement Input Probability Of Dissolution [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liability	0	10	10
Measurement Input, Expected Term [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liability	0
Measurement Input, Expected Term [Member] | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liability		0.50	0.83
Measurement Input, Expected Term [Member] | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liability		1	1.33
Measurement Input, Discount Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative liability	7.6	8.3	11.9

Fair Value Measurements - Sch_3

Fair Value Measurements - Schedule of Reconciliation of the Fair Value of the Derivative Liability Using Level 3 Significant Unobservable Inputs (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	$ (1,604)	$ 0
Fair value of derivative liability at issuance of convertible promissory note		(1,791)
Change in fair value of derivative liability (Note 7)		187
Ending balance	0	$ (1,604)
Change in the fair value of the derivative liability	(205)
Reclassification of derivative liability into convertible preferred stock resulting from conversion of convertible promissory note	$ 1,809

Grant Agreement - Additional In

Grant Agreement - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Grant Agreement [Line Items]
Restricted Cash	$ 1.6
BMSF Grant
Grant Agreement [Line Items]
Grant Received	10
Funding received	6	$ 4
Revenue from grant	7.8	1.6
Revenue since inception	9.4
Restricted Cash	0.6	2.3
Deferred revenue	$ 0.6	$ 2.3

Balance Sheet Details (Addition

Balance Sheet Details (Additional Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Depreciation expenses	$ 82	$ 1

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of property and equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property and Equipment [Line Items]
Property and equipment, cost	$ 1,159	$ 11
Accumulated depreciation	(83)	(1)
Property and equipment, net, Total	1,076	10
Laboratory equipment [Member]
Property and Equipment [Line Items]
Property and equipment, cost	856	11
Construction in progress [Member]
Property and Equipment [Line Items]
Property and equipment, cost	$ 303

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Taxes payable	$ 0	$ 91
Accrued paid time off	342	137
Accrued bonus	2,216	696
Other accrued liabilities	1,977	608
Accrued 401k	156	0
ESPP liability	66	0
Total accrued and other current liabilities	$ 4,757	$ 1,532

License Agreements - Additional

License Agreements - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Aug. 01, 2018
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issued	39,429,103	3,596,936
NIH Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment Of License Fee	$ 100,000
Potential milestone payments	2,100
Potential milestone payments	6,500
NIH Agreement | Research and Development Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment Of License Fee	200	$ 100
U W Two Thousand And Eighteen Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issued			192,276
Potential Payments For Future Development Regulatory And Sales Based Milestones	1,400
Total Milestone Payments	6,800
U W Two Thousand And Eighteen And U W Two Thousand And Twenty Agreement | License
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment Of License Fee	200	$ 300
U T Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payments	800
Potential milestone payments	3,800
UW Flu License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment Of License Fee	100
Aggregate Payments Related To Development	350
Aggregate Payments Related To Cumulative Net Sales Thresholds	$ 6,000
License Agreement Expiry Year	2041

Convertible Promissory Note - A

Convertible Promissory Note - Additional Information (Details) - USD ($)	Mar. 31, 2021	Mar. 19, 2021	Aug. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Debt Conversion [Line Items]
Convertible promissory note issued			$ 6,500,000
Accrued interest rate, per annum			6.00%
Promissory note maturity period			2 years	2 years
Derivatives liability, carrying value				$ 1,800,000	$ 1,600,000
Payments of Debt Issuance Costs				$ 36,000
Debt discount interest rate, effective percentage				23.80%
Loss on extinguishment of convertible promissory note				$ (754,000)	$ 0
Convertible Promissory Note
Debt Conversion [Line Items]
Debt Conversion, Converted Instrument, Amount			$ 140,000,000
Loss on extinguishment of convertible promissory note				$ 800,000
Series A3 Convertible Preferred Stock | Convertible Promissory Note
Debt Conversion [Line Items]
Share price, percentage			85.00%
Series B2 Convertible Preferred Stock [Member]
Debt Conversion [Line Items]
Share price, percentage	85.00%
Promissory note and derivative liability conversion into share		2,805,850
Shares issued price per share		$ 2.39846
Minimum [Member] | Series A3 Convertible Preferred Stock | Convertible Promissory Note
Debt Conversion [Line Items]
Proceeds from Convertible Debt			$ 5,000,000

Convertible Promissory Note - S

Convertible Promissory Note - Summary of Convertible Promissory Note (Details) - Promissory Note [Member] $ in Thousands	Dec. 31, 2020USD ($)
Summary Of Investment Holdings [Line Items]
Principal amount	$ 6,500
Discount related to the derivative liability and issuance costs	(1,553)
Net carrying amount of Convertible Promissory Note	$ 4,947

Convertible Promissory Note -_2

Convertible Promissory Note - Summary of Interest Expense of Convertible Promissory Note (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Convertible Promissory Note [Abstract]
Coupon interest at 6%	$ 86	$ 143
Accretion of discount and amortization of issuance costs	177	274
Total interest expense on Convertible Promissory Note	$ 263	$ 417

Convertible Preferred Stock a_3

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Schedule of Convertible Preferred Stock (Details) $ in Thousands	Dec. 31, 2020USD ($)shares
Class Of Stock [Line Items]
Share Authorized and Outstanding	54,039,749
Shares Issued and Outstanding	32,198,879
Convertible preferred stock issued upon conversion	7,748,113
Aggregate Liquidation Preference | $	$ 30,007
Carrying Value | $	$ 30,062
Series A-1
Class Of Stock [Line Items]
Share Authorized and Outstanding	49,089,955
Shares Issued and Outstanding	27,249,085
Convertible preferred stock issued upon conversion	6,557,031
Aggregate Liquidation Preference | $	$ 26,200
Carrying Value | $	$ 25,912
Series A-2
Class Of Stock [Line Items]
Share Authorized and Outstanding	4,949,794
Shares Issued and Outstanding	4,949,794
Convertible preferred stock issued upon conversion	1,191,082
Aggregate Liquidation Preference | $	$ 3,807
Carrying Value | $	$ 4,150

Convertible Preferred Stock a_4

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Additional Information (Details) - USD ($)	Aug. 04, 2021	Aug. 02, 2021	Mar. 31, 2021	Mar. 19, 2021	Aug. 31, 2021	Jul. 31, 2021	Feb. 28, 2021	Aug. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Reverse Stock Split			1-for-4.1557			1-for-4.1557
Preferred stock, shares issued									0	0
Preferred stock, par value									$ 0.0001	$ 0.0001
Preferred stock, shares outstanding									0	0
Common stock, shares authorized		500,000,000							500,000,000	78,000,000
Preferred stock, shares authorized		50,000,000							50,000,000	0
Proceeds from issuance of convertible preferred stock, net of issuance costs									$ 113,634,000	$ 0
Payments of Debt Issuance Costs									$ 36,000
Convertible promissory note issued								$ 6,500,000
Convertible preferred stock									16,351,336
Sale of common stock									39,429,103	3,596,936
Common Stock Shares Outstanding									39,175,279	2,639,026
Common stock, par value									$ 0.0001	$ 0.0001
Restricted common stock, vested									2,347,629	1,995,314
Restricted common stock,Expected to vest									0
Granted									6,177,633
Stock-based compensation									$ 29,031,000	$ 257,000
Stock-based compensation expense related to the ESPP									29,031,000	$ 257,000
Board of Directors Chairman
Class Of Stock [Line Items]
Accelerated vesting of shares	611,639
Exercise price range, lower range limit	$ 0.83
Exercise price range, upper range limit	$ 5.90
Stock-based compensation									21,000,000
Stock Options [Member]
Class Of Stock [Line Items]
Cash Recieved For Exercise Of Non Vested Options									$ 200,000
Weighted-average grant date fair value									$ 8.52	$ 1.06
Granted									6,177,633	271,405
Fair Value Of Option Granted Employee Service									$ 48,300,000	$ 300
Compensation expense recognition vesting period									3 years 4 months 28 days	4 years
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount									$ 39,400,000
Restricted Stock
Class Of Stock [Line Items]
Sale of common stock									269,694	269,694
Common stock, par value										$ 0.004
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount									$ 9,000,000
Restricted Stock | Management
Class Of Stock [Line Items]
Sale of common stock									2,347,629	2,347,629
Common stock, par value									$ 0.004
Restricted Stock Units (RSUs) [Member]
Class Of Stock [Line Items]
Weighted-average grant date fair value									$ 25.96
Granted									388,500	0
Fair Value Of Option Granted Employee Service									$ 10,100,000
2021 Stock Incentive Plan
Class Of Stock [Line Items]
Convertible preferred stock									4,600,000
Sale of common stock									50,000,000
Stock option granted vesting period									4 years
Stock option granted maximum term									10 years
Percentage Of Exercise Price To Fair Market Value Common Stock On Grant Date									100.00%
Percentage Increase In Common Stock Shares Reserved For Future Issuance									5.00%
Increase In Common Stock Shares Reserved For Future Issuance									1,971,455
Percentage Of Common Stock Outstanding									5.00%
2021 Stock Incentive Plan | Stock Options [Member]
Class Of Stock [Line Items]
Percentage Of Exercise Price To Fair Market Value Common Stock On Grant Date									110.00%
IPO [Member]
Class Of Stock [Line Items]
Common stock converted		21,634,898			21,634,898
Preferred stock, shares outstanding		89,908,215							0
Sale of common stock		12,133,333
Employee Stock [Member]
Class Of Stock [Line Items]
Convertible preferred stock									400,000
Sale of common stock									15,000,000
Percentage Increase In Common Stock Shares Reserved For Future Issuance									1.00%
Increase In Common Stock Shares Reserved For Future Issuance									394,291
Percentage Of Common Stock Outstanding									1.00%
Number of purchased shares by the employee									16,606
Stock-based compensation expense related to the ESPP									$ 100,000
Series A-1 Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Convertible preferred stock, shares issued							21,944,874
Series B Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares issued			35,764,462
Proceeds from issuance of convertible preferred stock, net of issuance costs			$ 92,700,000
Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, par value			$ 0.0001
Series B-1 Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares issued			32,958,612
Preferred stock, par value			$ 2.82172
Payments of Debt Issuance Costs			$ 350,000
Convertible promissory note issued			6,500,000
Accrued Liabilities			$ 200,000
Series B2 Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares issued			2,805,850
Promissory note and derivative liability conversion into share				2,805,850
Shares issued price per share				$ 2.39846
Debt Conversion, Converted Instrument, Rate			85.00%

Convertible Preferred Stock a_5

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Summary of the Status of the Options Issued Under the Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stockholders Equity Note [Abstract]
Option Pool Available for Grant ,Balance at December 31, 2020	541,411
Authorized increase in plan shares	22,634,965
Granted	(6,177,633)
Options Outstanding, Balance at December 31, 2020	641,427
Granted	6,177,633
Exercise of common stock options, (in shares)	227,333
Option Pool Available for Grant ,Balance at December 31, 2021	16,998,743	541,411
Options Outstanding, Balance at December 31, 2021	6,591,727	641,427
Weighted average exercise price per share, Balance at December 31, 2021	$ 8.04	$ 0.84
Vested and expected to vest as of December 31, 2021	6,591,727
Vested and exercisable at December 31, 2021	826,952
Weighted average exercise price per share, Balance at December 31, 2020	$ 0.84
Granted	8.52
Exercised (including early)	0.84
Vested and expected to vest as of December 31, 2021	8.04
Vested and exercisable at December 31, 2021	$ 5.71
Weighted average remaining contractual term (Years)	9 years 3 months 3 days	9 years 7 days
Vested and expected to vest as of December 31, 2021	9 years 3 months 3 days
Vested and exercisable at December 31, 2021	9 years 18 days
Aggregate intrinsic value, Balance at December 31, 2020	$ 0
Aggregate intrinsic value, Balance at December 31, 2021	101,725,631	$ 0
Exercised (including early)	1,012,104
Vested and expected to vest as of December 31, 2021	101,725,631
Vested and exercisable at December 31, 2021	$ 14,199,668

Convertible Preferred Stock a_6

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Schedule of Common Stock Reserved for Future Issuance (Details)	Dec. 31, 2021shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	16,351,336
Common Stock Options and Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	6,980,227
Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	8,187,715
2021 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	1,183,394

Convertible Preferred Stock a_7

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Schedule of Stock-based Compensation Expense for All Equity Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Stock-based compensation expense related to the ESPP	$ 29,031	$ 257
Research and Development Expense [Member]
Class Of Stock [Line Items]
Stock-based compensation expense related to the ESPP	2,710	137
General and Administrative [Member]
Class Of Stock [Line Items]
Stock-based compensation expense related to the ESPP	$ 26,321	$ 120

Convertible Preferred Stock a_8

Convertible Preferred Stock and Stockholders' Equity (Deficit) - Summary of Assumptions Used in Black-Scholes Model (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Risk-free rate of interest, Minimum	0.63%	0.31%
Risk-free rate of interest, Maximum	1.34%	1.40%
Expected stock price volatility, Minimum	84.20%	80.20%
Expected stock price volatility, Maximum	90.90%	86.40%
Dividend yield	0.00%	0.00%
Maximum [Member]
Class Of Stock [Line Items]
Expected term (years)	6 years 29 days	6 years 29 days
Minimum [Member]
Class Of Stock [Line Items]
Expected term (years)	5 years 9 months 7 days	5 years 10 months 24 days

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate and Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%
State income taxes, net of federal tax	1.00%	0.60%
Other permanent differences	(0.40%)	(0.30%)
Research and development tax credits	3.10%	3.80%
Research and Development Credit Permanent Adjustment	(0.60%)	(1.30%)
Stock-based compensation	(1.60%)	(0.30%)
Uncertain Tax Positions	(0.80%)	(1.00%)
Change in valuation allowance	(21.70%)	(22.50%)
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%	0.00%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets (Liabilities) Included in Other Assets in Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Net operating loss carryforwards	$ 12,623	$ 4,549
Research and development credits	2,349	790
Deferred revenue	126	515
Stock-based compensation	5,192	0
Other	533	226
Total deferred tax assets	20,823	6,080
Less: deferred tax liabilities	(280)	(3)
Less: valuation allowance	(20,543)	(6,077)
Deferred Tax Assets, Net, Total	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	$ 20,543	$ 6,077
Increase in valuation allowance	14,400
Research and development credits	$ 2,349	$ 790
Federal Operating Loss Carry forwards Expiration Period	2037
State Operating Loss Carry forwards Expiration Period	2035
Operating Loss Carry Forwards Expiration Period	2037
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 57,000
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	11,900
Research and Development Tax Credit Carryforwards | Federal
Operating Loss Carryforwards [Line Items]
Research and development credits	3,000
Research and Development Tax Credit Carryforwards | State
Operating Loss Carryforwards [Line Items]
Research and development credits	$ 168,000

Income Taxes - Summary of Unrec

Income Taxes - Summary of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, beginning of year	$ 263	$ 84
Additions based on tax positions relating to current year	495	242
Addtitions based on tax positions relating to prior year	0	0
Reductions for positions of prior years	0	(63)
Unrecognized tax benefits, end of year	$ 758	$ 263

Employee Savings Plan - Additio

Employee Savings Plan - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Employer discretionary contribution amount	$ 0	$ 0
Maximum
Defined Contribution Plan Disclosure [Line Items]
Percent of employees gross pay	90.00%