Document And Entity Information
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount
Statistical Measurement [Axis]
Note To Financial Statement Details Textual
Significant Accounting Policies
Provision for income taxes
Income Tax Expense (Benefit)
Provision for income taxes
Investment, Policy [Policy Text Block]
Note 3 - Fair Value of Financial Instruments 1
Cost-plus-fixed-fee [Member]
Related to cost-plus-fixed-fee.
Note 4 - Balance Sheet Components 1
Note 6 - Liabilities Related to Sale of Future Royalties 1
Note 7 - Leases 1
Firm Fixed-price Milestone [Member]
Related to firm fixed-price milestone.
Retirement Benefits [Text Block]
Note 9 - Stockholders' Equity 1
Note 10 - Equity Incentive Plans 1
The September 2021 ATM [Member]
Related to the September 2021 ATM.
Note 11 - Net Income (Loss) Per Share Attributable to Common Stockholders 1
Financial Instrument [Axis]
South San Francisco Real Estate [Member]
Related to South San Francisco real estate.
Note 12 - Segment Reporting 1
Facility in South San Francisco [Member]
Related to facility in South San Francisco.
Note 2 - Summary of Significant Accounting Policies
Note 3 - Fair Value of Financial Instruments
Minimum [Member]
us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Gross unrealized losses
Note 4 - Balance Sheet Components
Gross unrealized gains
Statistical Measurement [Domain]
Note 6 - Liabilities Related to Sale of Future Royalties
Maximum [Member]
us-gaap_SharePrice
Share Price (in dollars per share)
Note 7 - Leases
Note 9 - Stockholders' Equity
Foreign
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign
Note 10 - Equity Incentive Plans
Litigation Case [Domain]
us-gaap_BusinessAcquisitionSharePrice
Business Combination, Price Per Share (in dollars per share)
Note 12 - Income Taxes
Note 13 - Net Income (Loss) Per Share Attributable to Common Stockholders
us-gaap_IncreaseDecreaseInAccountsReceivable
Accounts receivable
United States
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
Note 14 - Segment Reporting
Note 3 - Fair Value of Financial Instruments - Financial Assets Measured on a Recurring Basis 1 (Details)
Note 4 - Balance Sheet Components - Cash and Cash Equivalents and Investments 1 (Details)
Note 4 - Balance Sheet Components - Prepaid Expenses and Other Current Assets 1 (Details)
Note 4 - Balance Sheet Components - Property and Equipment, Net 1 (Details)
Note 4 - Balance Sheet Components - Intangible Assets 1 (Details)
Note 4 - Balance Sheet Components - Estimated Future Amortization Expense 1 (Details)
Note 4 - Balance Sheet Components - Deferred Revenue, by Arrangement, Disclosure 1 (Details)
Note 4 - Balance Sheet Components - Accrued Liabilities 1 (Details)
Note 6 - Liabilities Related to Sale of Future Royalties - Deferred Revenue Activity 1 (Details)
Note 7 - Leases - Lease Liabilities Payment Obligations 1 (Details)
Note 7 - Leases - Operating Lease Expenses 1 (Details)
Note 9 - Stockholders' Equity - Shares of Common Stock Reserved for Issuance 1 (Details)
Note 9 - Stockholders' Equity - Summary of Warrants Outstanding 1 (Details)
Note 10 - Equity Incentive Plans - Summary of Stock Option Transactions 1 (Details)
Note 10 - Equity Incentive Plans - Assumptions of Options 1 (Details)
Note 10 - Equity Incentive Plans - Total Stock-based Compensation Recognized for Options 1 (Details)
Counterparty Name [Axis]
Note 11 - Net Income (Loss) Per Share Attributable to Common Stockholders - Calculation of Basic and Diluted Net (Loss) Income Per Share 1 (Details)
Change in valuation allowance, percent
Note 11 - Net Income (Loss) Per Share Attributable to Common Stockholders - Summary of Antidilutive Securities 1 (Details)
us-gaap_EffectiveIncomeTaxRateContinuingOperations
Provision for income taxes, percent
Note 12 - Segment Reporting - Schedule of Segment Reporting Information, by Segment 1 (Details)
U.S. federal taxes at statutory rate, percent
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
Note 2 - Summary of Significant Accounting Policies - Estimated Useful Lives (Details)
Weighted average exercise price, forfeited (in dollars per share)
At-the-market Facility [Member]
Related to at-the-market facility.
Note 3 - Fair Value of Financial Instruments - Financial Assets Measured on a Recurring Basis (Details)
Foreign rate differential, rate
Weighted average exercise price, canceled (in dollars per share)
Note 4 - Balance Sheet Components - Cash and Cash Equivalents and Investments (Details)
Weighted average exercise price, granted (in dollars per share)
Note 4 - Balance Sheet Components - Prepaid Expenses and Other Current Assets (Details)
Weighted average exercise price, exercised (in dollars per share)
Note 4 - Balance Sheet Components - Property and Equipment, Net (Details)
Note 4 - Balance Sheet Components - Intangible Assets (Details)
us-gaap_Dividends
Dividends
Note 4 - Balance Sheet Components - Estimated Future Amortization Expense (Details)
Note 4 - Balance Sheet Components - Deferred Revenue, by Arrangement, Disclosure (Details)
Note 4 - Balance Sheet Components - Accrued Liabilities (Details)
Note 6 - Liabilities Related to Sale of Future Royalties - Deferred Revenue Activity (Details)
Issuance of treasury stock under ESPP
The amount of treasury stock issued during the period in connection with an employee stock purchase plan.
Income Tax Jurisdiction [Domain]
Note 7 - Leases - Lease Liabilities Payment Obligations (Details)
Note 7 - Leases - Operating Lease Expenses (Details)
Note 9 - Stockholders' Equity - Shares of Common Stock Reserved for Issuance (Details)
Note 9 - Stockholders' Equity - Summary of Warrants Outstanding (Details)
Note 10 - Equity Incentive Plans - Summary of Stock Option Transactions (Details)
Note 10 - Equity Incentive Plans - Assumptions of Options (Details)
Note 10 - Equity Incentive Plans - Total Stock-based Compensation Recognized for Options (Details)
Proceeds from issuance of treasury stock under the employee stock purchase plan
The amount of proceeds from stock plans through treasury stock.
Note 12 - Income Taxes - Schedule of Income Before Income Tax (Details)
Note 12 - Income Taxes - Components of Income Tax Expense (Details)
Note 12 - Income Taxes - Components of Deferred Tax Assets (Details)
Other nondeductible items, percent
Interest income
Interest income
Financial Instruments [Domain]
Note 12 - Income Taxes - Reconciliation of Effective Tax Rate (Details)
us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount
Note 12 - Income Taxes - Income Taxes Paid (Details)
Note 12 - Income Taxes - Schedule of State and Local Income Tax (Details)
Note 12 - Income Taxes - Unrecognized Tax Benefits (Details)
Note 13 - Net Loss Per Share Attributable to Common Stockholders - Calculation of Basic and Diluted Net (Loss) Income Per Share (Details)
Note 13 - Net Loss Per Share Attributable to Common Stockholders - Summary of Antidilutive Securities (Details)
Litigation Case [Axis]
Note 14 - Segment Reporting - Schedule of Segment Reporting Information, by Segment (Details)
Leasehold Improvements [Member]
State taxes (net of federal benefit), percent
Notes To Financial Statements
Prior year true-up, percent
Notes To Financial Statements [Abstract]
Counterparty Name [Domain]
vxrt_RoyaltyInterestCovenantShortfallInRoyaltyPayments
Royalty Interest, Covenant, Shortfall in Royalty Payments
Represents the covenant for royalty interest relating to shortfalls in royalty payments.
vxrt_RoyaltyInterestCovenantCumulativeRemainingShortfallAmount
Royalty Interest, Covenant, Cumulative Remaining Shortfall Amount
Represents the covenant for the cumulative remaining shortfall amount in a royalty interest agreement. Calculated using the aggregate amount of remaining shortfall for each annual period.
Stock-based compensation, percent
us-gaap_SharesOutstanding
Balances (in shares)
Balances (in shares)
Unbilled Receivables [Member]
Represents information pertaining to unbilled receivables.
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions
Segment Reporting [Text Block]
Royalty Payment, Interest, Second Period [Member]
Represents the second period of royalty repayment interest.
Royalty Payment, Interest, First Period [Member]
Represents the first period of royalty repayment interest.
RA Capital Healthcare Fund 2024 [Member]
Represents the securities purchase agreement with RA Capital Healthcare Fund, L.P. in the year 2024.
HHS Barda [Member]
Represents information pertaining to HHS Barda.
Award Type [Axis]
Segment Reporting [Table Text Block]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cost-plus-fixed-fees Arrangement Under ATI-RRPV Contract [Member]
Related to cost-plus-fixed-fees arrangement underATI-RRPV contract.
Preferred stock: $0.0001 par value; 5,000,000 shares authorized; none issued and outstanding as of March 31, 2026 and December 31, 2025
Plan Name [Axis]
us-gaap_Liabilities
Total liabilities
Plan Name [Domain]
Defined Benefit Plan [Table]
Reimbursable Purchase Agreement Commitment to Vendor [Member]
Related to reimbursable purchase agreement commitment to vendor.
us-gaap_AllocatedShareBasedCompensationExpense
Share-Based Payment Arrangement, Expense
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and stockholders’ equity
Consolidation Items [Axis]
Cash and Cash Equivalents [Axis]
Segment Reporting [Table]
Non Cash Royalty Revenue [Member]
Non cash usage-based right to asset.
us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets
Prepaid expenses and other assets
Internal Research and Development Costs [Member]
Represents information pertaining to the internal research and development costs.
Process Development Program [Member]
Represents information pertaining to the process development program.
us-gaap_ShareBasedCompensation
Stock-based compensation
Subsequent Event [Member]
Covid-19 Program [Member]
Represents information pertaining to the Covid-19 program.
Norovirus Program [Member]
Represents information pertaining to the Norovirus Program.
Consolidation Items [Domain]
Preclinical Research [Member]
Represents information pertaining to preclinical research.
Other Programs [Member]
Represents information pertaining to other programs.
vxrt_NoncashRevenueRelatedToSaleOfFutureRoyalties
Non-cash revenue related to sale of future royalties
Amount of non-cash accounted for as Revenue in relation to the sale of future royalties.
Authorized (in shares)
Lessee, Lease, Description [Table]
Share-Based Payment Arrangement [Text Block]
Issuance of treasury stock under ESPP (in shares)
The amount of shares of treasury stock issued during the period in connection with an employee stock purchase plan.
Lease Contractual Term [Axis]
Lease Contractual Term [Domain]
vxrt_GrossProceedsFromIssuanceOfCommonStock
Gross Proceeds from Issuance of Common Stock
The gross cash inflow from the additional capital contribution to the entity before deducting underwriting discounts, commission, and offering expenses.
Change in operating assets and liabilities:
us-gaap_IncreaseDecreaseInAccountsPayable
Accounts payable
Preferred stock, shares issued (in shares)
us-gaap_FiniteLivedIntangibleAssetUsefulLife
Finite-Lived Intangible Asset, Useful Life (Year)
Preferred stock, shares outstanding (in shares)
Preferred Stock, Shares Outstanding, Ending Balance (in shares)
Preferred stock, shares authorized (in shares)
Preferred Stock, Shares Authorized (in shares)
Preferred stock, par value (in dollars per share)
Preferred Stock, Par or Stated Value Per Share (in dollars per share)
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Net increase (decrease) in cash and cash equivalents
Cash and cash equivalents
vxrt_ContractWithCustomerLiabilityAmountCollectedOrInvoiced
Amounts collected or invoiced
The amount of contract with customer liabilities collected or invoiced.
Money market funds, Fair Value
Common Warrants [Member]
Represents information pertaining to common warrants.
Lease for Facility in South San Francisco Commenced in First Quarter of 2023 [Member]
Represents lease for facility in South San Francisco, California in first quarter of 2023.
New Accounting Pronouncements, Policy [Policy Text Block]
Laboratory Equipment [Member]
Property, plant, and equipment classified as laboratory equipment.
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and cash equivalents at beginning of the period
Cash and cash equivalents at end of the period
Schedule of Property, Plant, and Equipment, Useful Life [Table Text Block]
Tabular disclosure of the useful life of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale, which acts as the basis for calculation of depreciation.
Concentration Risk, Credit Risk, Policy [Policy Text Block]
Antidilutive Securities, Name [Domain]
Comprehensive income (loss):
Statement [Table]
Reclassification, Comparability Adjustment [Policy Text Block]
Prepaid insurance
us-gaap_PrepaidInsurance
California Franchise Tax Board [Member]
us-gaap_PrepaidRoyalties
Prepaid Royalties
The 2024 Inducement Award Plan [Member]
Relating to the 2024 Inducement Award Plan.
Income Tax Authority, Name [Axis]
Income Tax Authority, Name [Domain]
Prepaid clinical services, long-term
Prepaid Expense Other, Noncurrent
The 2019 Plan [Member]
Represents information pertaining to the 2019 Equity Incentive Plan.
National Tax Agency, Japan [Member]
Investments, Fair Value Disclosure
Intellectual Property [Member]
Prepaid rent
us-gaap_PrepaidRent
Australian Taxation Office [Member]
Clinical Research Organization [Member]
Legal entity of party involved in collaborative agreement.
New York State Division of Taxation and Finance [Member]
Schedule of Common Stock Reserved for Issuance [Table Text Block]
Tabular disclosure of common stock reserved for issuance.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Balance, Weighted average grant date fair value (in dollars per share)
Balance, Weighted average grant date fair value (in dollars per share)
Granted, Weighted average grant date fair value (in dollars per share)
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
HealthCare Royalty Partners III, L.P. [Member]
Represents the legal entity, HealthCare Royalty III, L.P.
Product and Service [Domain]
Product and Service [Axis]
Laboratory equipment (in years) (Year)
Accrued clinical and manufacturing expenses
Amount of accrued clinical and manufacturing expenses due within one year.
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Undiscounted total
Revenue [Text Block]
The entire disclosure for revenues at the end of the reporting period, and description and amounts of significant changes that occurred during the reporting period.
vxrt_RoyaltyPercentage
Royalty Percentage
Royalty percentage received on net sales.
us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent
Operating Lease, Weighted Average Discount Rate, Percent
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)
vxrt_OperatingLossCarryforwardsSubjectToExpiration
Operating Loss Carryforwards, Subject to Expiration
The amount of operating loss carryforwards subject to expiration.
BARDA [Member]
This item represents contractual agreements with the U.S. Office of Biomedical Advanced Research and Development Authority ("BARDA").
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
2027
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Number of options outstanding, forfeited (in shares)
us-gaap_AccountsPayableCurrentAndNoncurrent
Accounts Payable
vxrt_OperatingLossCarryforwardCarriedForwardIndefinitely
Operating Loss Carryforward, Carried Forward Indefinitely
The amount of operating loss carryforward carried forward indefinitely.
Commercial Paper [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
Number of options outstanding, canceled (in shares)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Shares available for grant, balance (in shares)
Shares available for grant, balance (in shares)
us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear
2026 (nine months remaining)
vxrt_RoyaltyWithholdingTax
Royalty Withholding Tax
Percentage of tax withheld from royalty income.
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]
Measurement Frequency [Axis]
vxrt_LicenseAgreementTotalTransactionPrice
License Agreement, Total Transaction Price
The total transaction price for the license agreement.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)
Number of options outstanding, beginning balance (in shares)
Number of options outstanding, balance (in shares)
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree
2029
vxrt_LicenseAgreementConsideration
License Agreement, Consideration
The amount of consideration for the license agreement.
Commitments and Contingencies Disclosure [Text Block]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share)
Weighted average exercise price, balance (in dollars per share)
Weighted average exercise price, balance (in dollars per share)
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
2028
Nature of Expense [Axis]
Statement [Line Items]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour
2029
Fair Value Hierarchy and NAV [Axis]
Common stock, shares issued (in shares)
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Common stock, shares outstanding (in shares)
Award Type [Domain]
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Risk-free interest rate
Common stock, shares authorized (in shares)
Common Stock, Shares Authorized (in shares)
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
us-gaap_IncreaseDecreaseInPrepaidExpensesOther
Prepaid clinical services, long-term
Expected volatility
Dividend yield
Daiichi Sankyo [Member]
This item represents transactions between the Company and Daiichi Sankyo.
Schedule of Accrued Liabilities [Table Text Block]
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Common stock: $0.0001 par value; 350,000,000 shares authorized as of March 31, 2026 and December 31, 2025; 242,169,130 shares issued and 241,414,053 shares outstanding as of March 31, 2026 and 240,742,681 shares issued and 240,494,594 shares outstanding as of December 31, 2025
us-gaap_ProceedsFromIssuanceOrSaleOfEquity
Proceeds from Issuance or Sale of Equity
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
2028
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
2029
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
2027
Cash, Cash Equivalent, and Investment [Table Text Block]
Net proceeds from issuance of common stock
Proceeds from Issuance of Common Stock
Securities into which warrants are convertible (in dollars per share)
Accounts payable
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Current:
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear
2026 (nine months remaining)
Deferred:
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
2029
us-gaap_TableTextBlock
Notes Tables
us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive income (loss)
Short-term investments
Accrued professional and consulting services
Subsequent Events [Text Block]
Concentration Risk Type [Axis]
Other accrued current liabilities
Total
Accrued compensation
Significant Accounting Policies [Text Block]
Lease liability
vxrt_DeferredTaxAssetsLeaseLiabilities
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from lease liabilities.
Daiichi Sankyo Collaberation and License Agreement [Member]
Royalty revenue from the sale of Inavir in Japan, pursuant to a collaboration and license agreement that Aviragen entered into with Daiichi Sankyo Company, Limited ("Daiichi Sankyo") in 2009.
us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Less: imputed interest
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted-Average Remaining Contractual Term (Year)
Operating lease liability, net of current portion
Operating lease liability, net of current portion
us-gaap_OperatingLeaseLiability
Present value of future minimum payments
Other liabilities, current portion
Current portion of operating lease liability
Current portion of operating lease liability
Capitalized research and development
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from capitalized research and development.
Liabilities Related to Sale of Future Royalties [Text Block]
The entire disclosure for the liabilities related to the sale of future royalties per the royalty interest acquisition agreement.
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
Accounts Receivable [Member]
vxrt_FinitelivedIntangibleAssetRemainingLife
Finite-Lived Intangible Asset, Remaining Life (Year)
The remaining life of finite-lived intangible assets.
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term (Year)
Expected term (in years) (Year)
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]
Concentration Risk Type [Domain]
vxrt_ProceedsFromIssuanceOrSaleOfEquityNet
Proceeds from Issuance or Sale of Equity, Net
The net cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.
Accounts Payable [Member]
vxrt_RoyaltyInterestAdditionalRoyaltiesDueEachYear
Royalty Interest, Additional Royalties Due Each Year
Amount of additional royalties due each year.
vxrt_RoyaltyInterestPercentageOfAdditionalRoyaltiesDueEachYear
Royalty Interest, Percentage of Additional Royalties Due Each Year
Percentage of additional royalties due each year.
HCRP [Member]
HealthCare Royalty Partners are purchasers of royalty rights.
Amortized Cost
vxrt_DebtNoncashRoyaltyRevenuePaid
Non-cash royalty revenue paid to HCRP
Non-cash interest expense recognized
Amount of non-cash interest expense recognized in relation to the sale of future royalties.
March 2025 ATM with Citizens and B. Riley [Member]
Represents the at-the-market offering with Citizens and B. Riley entered in March 2025
Income Tax Jurisdiction, Domestic Federal [Member]
Proceeds from sale of property and equipment
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]
vxrt_OpenMarketSaleAgreementMaximumAggregateOfferingPrice
Open Market Sale Agreement, Maximum Aggregate Offering Price
The maximum aggregate offering price pursuant to the open market sale agreement.
Income Tax Jurisdiction, Domestic State and Local [Member]
vxrt_LiabilityRelatedToSaleOfFutureRoyalties
Total liability related to sale of future royalties, start of period
Total liability related to sale of future royalties, end of period
Amount of liability associated with the sale of future royalties.
vxrt_LesseeOperatingLeaseNumberOfLeases
Lessee, Operating Lease, Number of Right-of-Use Leases
Number of right-of-use operating leases.
Offsetting Assets [Table]
vxrt_EquityOfferingMaximumAmount
Equity Offering, Maximum Amount
The maximum value of the equity offering.
Statement of Stockholders' Equity [Abstract]
Intangible Asset, Finite-Lived, Class [Axis]
Loss Contingencies [Table]
vxrt_OpenMarketSaleAgreementSalesCommissionPercentage
Open Market Sale Agreement, Sales Commission, Percentage
The percentage of sales commission pursuant to the open market sale agreement.
Intangible Asset, Finite-Lived, Class [Domain]
Class of Warrant or Right [Axis]
Prepaid Expenses and Prepaid Clinical Services [Policy Text Block]
Disclosure of accounting policy for prepaid expenses and prepaid clinical services.
Class of Warrant or Right [Domain]
Statement of Cash Flows [Abstract]
vxrt_LicenseAgreementStockToBePurchasedPerShare
License Agreement, Stock To Be Purchased, Per Share (in dollars per share)
The per share value of stock to be purchased under license agreement.
vxrt_LicenseAgreementStockToBePurchasedAmount
License Agreement, Stock To Be Purchased, Amount
The value of stock to be purchased under license agreement.
License Agreement and Purchase Agreement [Member]
Related to license agreement and purchase agreement.
vxrt_LicenseAgreementProceedsToBeReceived
License Agreement, Proceeds To Be Received
The value of proceeds to be received under license agreement.
vxrt_LicenseAgreementFeeToBeReceived
License Agreement, Fee To Be Received
The amount of fee to be received under license agreement.
Equity Components [Axis]
Sanofi [Member]
Represents Sanofi.
Unrealized loss on available-for-sale investments, net of tax
vxrt_EffectiveIncomeTaxRateReconciliationTaxCreditsAmount
Tax credits
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.
Share-Based Payment Arrangement [Policy Text Block]
Proceeds from issuance of common stock upon exercise of stock options
Proceeds from Stock Options Exercised
Changes in unrecognized tax benefits
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in unrecognized tax benefits.
Equity Component [Domain]
Offsetting Liabilities [Table]
Fair Value, Inputs, Level 2 [Member]
Fair Value, Inputs, Level 3 [Member]
vxrt_IncomeTaxStateIncomeTaxesPaidPercentageOfAllStates
Income tax, percent
The amount of state income taxes paid expressed as a percentage of all state income taxes paid.
Equity [Text Block]
Sanofi Merger With Dynavax [Member]
Represents the Sanofi merger with Dynavax.
Fair Value, Inputs, Level 1 [Member]
AOCI Attributable to Parent [Member]
Securities into which warrants are convertible (in shares)
Class of Warrant or Right, Outstanding (in shares)
Additional Paid-in Capital [Member]
Retained Earnings [Member]
Income Tax Jurisdiction, Foreign [Member]
Foreign Currency Transactions and Translations Policy [Policy Text Block]
Property and equipment, net
Property and equipment, net
Property and equipment, gross
Acquisition of property and equipment included in accounts payable and accrued expenses
Subsequent Event Type [Domain]
Subsequent Event [Table]
Subsequent Event Type [Axis]
Property, Plant, and Equipment [Policy Text Block]
Sale of Stock [Axis]
Stock-based compensation
Stockholders’ equity:
Investments and Cash, Fair Value Disclosure
Represents the fair value amount of investments and cash.
vxrt_GovernmentContractAwardAmountAllottedAndAvailable
Government Contract, Award Amount, Allotted and Available
Amount of government contract that is currently allotted and available which comprises amount received, receivable, and to be received unless condition for government contract is not met. Includes, but is not limited to, government grant, assistance, incentive, award, subsidy, and loan.
vxrt_GovernmentContractAmountAuthorizedMilestones
Government Contract, Amount, Authorized Milestones
Amount of government contract available to be awarded from authorized milestones which comprises amount received, receivable, and to be received unless condition for government contract is not met. Includes, but is not limited to, government grant, assistance, incentive, award, subsidy, and loan.
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
vxrt_GovernmentContractAwardAmountInitialAwardFixedFee
Government Contract, Award Amount, Initial Award Fixed Fee
Amount of government contract initial fixed fee awarded that comprises amount received, receivable, and to be received unless condition for government contract is not met. Includes, but is not limited to, government grant, assistance, incentive, award, subsidy, and loan.
vxrt_GovernmentContractAdditionalFundingPossible
Government Contract, Additional Funding Possible
Additional amount of funding possible if study continues for government contract awarded that comprises amount received, receivable, and to be received unless condition for government contract is not met. Includes, but is not limited to, government grant, assistance, incentive, award, subsidy, and loan.
Fair Value Disclosures [Text Block]
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Share-Based Payment Arrangement, Option [Member]
Supplemental disclosure of non-cash investing and financing activity:
us-gaap_AccountsReceivableNet
Accounts Receivable, after Allowance for Credit Loss
Current liabilities:
us-gaap_CurrentIncomeTaxExpenseBenefit
Total Current
us-gaap_LiabilitiesCurrent
Total current liabilities
us-gaap_CurrentFederalTaxExpenseBenefit
Federal
us-gaap_CurrentForeignTaxExpenseBenefit
Foreign
us-gaap_CurrentStateAndLocalTaxExpenseBenefit
State
Accounts receivable
Customer Concentration Risk [Member]
us-gaap_TaxCreditCarryforwardAmount
Tax Credit Carryforward, Amount
Change in Unrecognized Tax Benefit, Reasonably Possible [Table]
Lease, Cost [Table Text Block]
Tax Credit Carryforward [Axis]
Tax Credit Carryforward, Name [Domain]
us-gaap_GainLossOnDispositionOfAssets1
Loss on sale of property and equipment
Accrued Clinical And Manufacturing Expenses Policy [Policy Text Block]
Disclosure of accounting policy for inclusion of significant items in the accrued clinical and manufacturing expense report caption.
Lessee, Leases [Policy Text Block]
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Less: accumulated depreciation
Collaboration Revenue [Member]
Represents the collaboration revenue.
Accumulated other comprehensive loss
us-gaap_PaymentsToAcquireInvestments
Purchases of investments
us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Less: accumulated amortization
Research and Development [Member]
In relation to research and development.
Other Accrued Liabilities [Member]
In relation to other accrued liabilities.
Prepaid Expenses [Member]
In relation to prepaid expenses
vxrt_GainLossOnModificationOfLeaseLiability
Gain (Loss) on Modification of Lease Liability
Gain on modification of lease liability
The amount of gain (loss) from the modification of lease liability.
General and administrative
General and administrative
vxrt_LicenseAgreementTotalTransactionCosts
License Agreement, Total Transaction Costs
The total amount of transaction costs for the license agreement.
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Income (loss) before income taxes
Right of Use for Office and Manufacturing Facilities with Initial Terms Exceeding One Year [Member]
Represents information regarding right of use for office and manufacturing facilities with initial terms exceeding one year.
Clinical Research Organizer and Analytic Testing Vendor [Member]
Represents the Clinical Research Organizer and Analytic Testing Vendor.
Additional paid-in capital
vxrt_LicenseAgreementPremium
License Agreement, Premium
The premium expense for the license agreement.
Use of Estimates, Policy [Policy Text Block]
Prepaid expenses and other current assets
Prepaid expenses and other current assets
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)
Clinical Research Organization and Analytical Testing Vendor [Member]
Represents a clinical research organization and an analytical testing vendor.
Issuance of common stock under ESPP
Issuance of common stock
Stock Issued During Period, Value, New Issues
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of property and equipment
Lessee, Operating Leases [Text Block]
Goodwill and Intangible Assets, Policy [Policy Text Block]
vxrt_PremiumPaidForIssuanceOfEquity
Premium Paid for Issuance of Equity
The premium paid for the issuance of equity.
Current assets:
Money Market Funds [Member]
Issuance of common stock upon exercise of stock options
Foreign, percent
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to adjustments classified as foreign.
us-gaap_AssetsCurrent
Total current assets
Foreign
vxrt_EffectiveIncomeTaxRateReconciliationForeignAmount
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to adjustments classified as foreign.
Release of common stock for vested restricted stock units
Massachusetts Tax Authority [Member]
Represents the Massachusetts tax authority.
Issuance of common stock under ESPP (in shares)
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)
Schedule of Income Taxes Paid [Table Text Block]
The tabular disclosure for the income tax paid.
us-gaap_LitigationSettlementAmountAwardedToOtherParty
Litigation Settlement, Amount Awarded to Other Party
Issuance of common stock (in shares)
Stock Issued During Period, Shares, New Issues (in shares)
Changes in unrecognized tax benefits, percent
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in unrecognized tax benefits.
Restricted Stock Units (RSUs) [Member]
RA Capital Healthcare Fund 2025 [Member]
Represents the securities purchase agreement with RA Capital Healthcare Fund, L.P. in the year 2025.
Issuance of common stock upon exercise of stock options (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)
Number of options outstanding, exercised (in shares)
Fair Value Measurement Inputs and Valuation Techniques [Table]
Release of common stock for vested restricted stock units (in shares)
us-gaap_Depreciation
Depreciation
Facility in Burlingame, California [Member]
Related to facility in Burlingame, California.
Schedule of Income Tax by State [Table Text Block]
The tabular disclosure for the income tax by state.
us-gaap_TreasuryStockSharesAcquired
Repurchase of common stock to satisfy tax withholding (in shares)
Cash flows from operating activities:
Cash flows from investing activities:
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash used in operating activities
Cash flows from financing activities:
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash (used in) provided by investing activities
us-gaap_SharesIssuedPricePerShare
Shares Issued, Price Per Share (in dollars per share)
Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block]
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash used in financing activities
Total assets
Debt Instrument, Redemption, Period [Axis]
Warrants Expiring March 2025 [Member]
Represents information related to warrants expiring March 2025.
Debt Instrument, Redemption, Period [Domain]
Proceeds from maturities of investments
us-gaap_GoodwillImpairmentLoss
Goodwill, Impairment Loss
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member]
Developed Technology Rights [Member]
Operating Segments [Member]
Accounting Policies [Abstract]
Long-Lived Asset, Excluding Intangible Asset and Goodwill, Impairment and Disposal [Policy Text Block]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]
US Treasury Securities [Member]
Receivable [Policy Text Block]
us-gaap_DeferredForeignIncomeTaxExpenseBenefit
Foreign
Income Statement [Abstract]
us-gaap_DeferredFederalIncomeTaxExpenseBenefit
Federal
us-gaap_UnrecognizedTaxBenefits
Unrecognized Tax Benefits
Beginning Balance
Ending Balance
us-gaap_DeferredIncomeTaxLiabilities
Total deferred tax liabilities
us-gaap_NumberOfReportableSegments
Number of Reportable Segments
us-gaap_DeferredIncomeTaxExpenseBenefit
Total Deferred
vxrt_CommonStockCapitalSharesReservedForFutureIssuanceIncrease
Common Stock, Capital Shares Reserved for Future Issuance, Increase (in shares)
The increase in the number of common shares reserved for future issuance.
us-gaap_PurchaseObligation
Purchase Obligation
us-gaap_TreasuryStockCommonValue
Treasury stock at cost, 755,077 shares as of March 31, 2026 and 248,087 shares as of December 31, 2025
Additions based on tax positions related to the current year
Treasury Stock, Common, Shares (in shares)
Balances (in shares)
Balances (in shares)
Treasury Stock, Common [Member]
us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
Decreases related to prior years’ tax positions
Deferred Revenue [Domain]
Net income (loss)
Net income (loss)
Adjustments and reconciling items
Deferred Revenue Arrangement Type [Axis]
us-gaap_GovernmentAssistanceAwardAmount
Government Assistance, Award Amount
us-gaap_AmortizationOfIntangibleAssets
Intangible Asset, Finite-Lived, Amortization Expense
Offering costs
us-gaap_AreaOfRealEstateProperty
Area of Real Estate Property (Acre)
us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit
State
us-gaap_DeferredTaxAssetsGross
Total deferred tax assets
us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense
Income Tax Disclosure [Text Block]
Proceeds from issuance of common stock under the employee stock purchase plan
Proceeds from Stock Plans
Share-Based Payment Arrangement [Member]
Net operating loss carry-forwards
Accounting Standards Update and Change in Accounting Principle [Table]
us-gaap_DeferredTaxAssetsNet
Deferred tax assets net of valuation allowance
Foreign rate differential
U.S. federal taxes at statutory rate
Research and development tax credits
us-gaap_TreasuryStockValueAcquiredCostMethod
Repurchase of common stock to satisfy tax withholding
Other nondeductible items
Supplemental Balance Sheet Disclosures [Text Block]
Collaborative Arrangement and Arrangement Other than Collaborative [Axis]
us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value
State taxes (net of federal benefit)
Income tax
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number (in shares)
Accruals, reserves and other
Prior year true-up
us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
Stock based compensation
us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost
Stock-based compensation
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price (in dollars per share)
The March 2025 ATM [Member]
Represents the March 2025 ATM offering.
Fair Value Hierarchy and NAV [Domain]
vxrt_EffectiveIncomeTaxRateReconciliationTaxCreditsPercent
Tax credits, percent
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.
Measurement Frequency [Domain]
us-gaap_OpenTaxYear
Open Tax Year
Other income (expense):
Statement of Financial Position [Abstract]
us-gaap_DeferredTaxAssetsValuationAllowance
Valuation allowance
us-gaap_IncomeTaxesPaidNet
Total Taxes Paid
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]
us-gaap_DeferredTaxLiabilities
Net deferred tax assets
us-gaap_DeferredTaxLiabilitiesLeasingArrangements
Right-of-use assets
us-gaap_TangibleAssetImpairmentCharges
Tangible Asset Impairment Charges
Fair Value, Recurring [Member]
us-gaap_DeferredTaxLiabilitiesOtherFiniteLivedAssets
Intangible assets
Other long-term assets
Warrants Expiring December 2026 [Member]
Represents information pertaining to warrants expiring in December 2026.
us-gaap_IncreaseDecreaseInDeferredRevenue
Deferred revenue
us-gaap_DeferredRevenue
Deferred Revenue
The 2022 ESPP [Member]
Represents the 2022 Employee Stock Purchase Plan.
Warrant [Member]
vxrt_LesseeShortTermLeaseNumberOfLeases
Lessee, Short-term Lease, Number of Leases
The number of short-term leases of the lessee.
Document Type
vxrt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForGrantDecreaseFromGrants
Shares available for grant, granted (in shares)
Represents the decrease in the shares available for grant attributable to shares granted during the period.
Operating expenses:
Document Information [Line Items]
us-gaap_ConcentrationRiskPercentage1
Concentration Risk, Percentage
us-gaap_DefinedContributionPlanCostRecognized
Defined Contribution Plan, Cost
Shares available for grant, canceled (in shares)
Represents the change in the shares available for grant attributable to shares canceled during the period under the plan.
us-gaap_LesseeOperatingLeaseRenewalTerm
Lessee, Operating Lease, Renewal Term (Year)
Deferred collaboration revenue, net of current portion
Deferred Revenue, Noncurrent
us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1
Operating Lease, Weighted Average Remaining Lease Term (Year)
Document Information [Table]
Deferred revenue
Deferred Revenue, Current
Current portion
Shares available for grant, forfeited (in shares)
Represents the change in the shares available for grant attributable to shares forfeited during the period under the plan.
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation (in shares)
us-gaap_IncomeTaxPaidForeignAfterRefundReceived
Foreign
Antidilutive Securities [Axis]
us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Weighted Average Number of Shares Outstanding, Diluted, Adjustment (in shares)
Diluted (in shares)
Weighted average shares used to compute net income (loss) per share, diluted (in shares)
Employee Stock Purchase Plan [Member]
Represents employee stock purchase plan.
us-gaap_OperatingExpenses
Total operating expenses
Purchase Commitment, Excluding Long-Term Commitment [Domain]
Net income (loss) per share:
Purchase Commitment, Excluding Long-Term Commitment [Axis]
Basic (in shares)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]
Antidilutive Security, Excluded EPS Calculation [Table]
Election Payment [Member]
Relating to election payment.
Research Tax Credit Carryforward [Member]
Basic (in dollars per share)
Basic (in dollars per share)
Research and Development Expense, Policy [Policy Text Block]
vxrt_ContractWithCustomerLiabilityRevenueRecognizedIncludingOpeningBalance
Revenue recognized
Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.
State and Local
Adjustment to operating lease right-of-use asset from lease modification
Represents the adjustment to right-of-use asset from lease modification.
Effective Income Tax Rate Reconciliation [Table]
us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived
State and Local
Collaborative Arrangement and Arrangement Other than Collaborative [Domain]
Earnings Per Share, Policy [Policy Text Block]
us-gaap_IncomeTaxPaidFederalAfterRefundReceived
Federal
Office Equipment [Member]
Foreign
Income Tax Jurisdiction [Axis]
Intangible assets, net
Intangible assets, net
us-gaap_FiniteLivedIntangibleAssetsNet
Total
Customer [Domain]
Intangible assets, gross
Depreciation and amortization
Amendment Flag
Himmelberg V. Vaxart, Inc. et al. [Member]
Represents the Himmelberg V. Vaxart, Inc. et al.
us-gaap_SubleaseIncome
Sublease income
Common Stock [Member]
us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium
Net accretion of discounts on investments
Goodwill
Goodwill
Long-Lived Asset, Class [Domain]
Legal Entity [Axis]
Variable lease cost
Number of options outstanding, granted (in shares)
vxrt_SharebasedCompensationArrangementBySharebasedPaymentAwardNonoptionEquityInstrumentsReleased
Number of RSUs outstanding, release (in shares)
Number of non-option equity instruments released by participants.
us-gaap_FinancialLiabilitiesFairValueDisclosure
Financial Liabilities Fair Value Disclosure
Operating lease cost
Short-term lease cost
us-gaap_LeaseCost
Total lease cost
Construction in Progress [Member]
Business Combination [Domain]
Released, Weighted average grant date fair value (in dollars per share)
Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were released.
Entity Tax Identification Number
Business Combination [Axis]
Disaggregation of Revenue [Table]
Entity [Domain]
Entity Central Index Key
us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Business Combination, Voting Equity Interest Acquired, Percentage
Entity Registrant Name
Entity Incorporation, State or Country Code
Unrealized loss on available-for-sale investments
Research and development
Research and Development Expense
Entity Filer Category
Entity Emerging Growth Company
us-gaap_DebtSecuritiesAvailableForSaleGainLoss
Debt Securities, Available-for-Sale, Gain (Loss)
Entity Small Business
us-gaap_OperatingIncomeLoss
Operating income (loss)
Cash and Cash Equivalents [Domain]
us-gaap_OperatingLossCarryforwards
Operating Loss Carryforwards
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
us-gaap_SegmentReportingOtherItemAmount
Other segment items(A)
us-gaap_Revenues
Revenues
Revenue:
us-gaap_BusinessCombinationConsiderationTransferred1
Business Combination, Consideration Transferred
Entity Address, State or Province
Entity Address, City or Town
Accumulated deficit
Entity Address, Address Line One
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
City Area Code
us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation
Shares acquired to settle employee tax withholding liabilities
Local Phone Number
Government Assistance, Type [Domain]
Entity Address, Postal Zip Code
Accrued and other liabilities
Unbilled receivable from government contracts
Unbilled Receivables, Current
Class of Stock [Axis]
Government Assistance, Type [Axis]
Estimated Fair Value
Revenue [Policy Text Block]
Current portion of liability related to sale of future royalties
vxrt_LiabilityRelatedToSaleOfFutureRoyaltiesCurrent
Current portion
Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to the selling costs of future royalties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).
Liability related to sale of future royalties, net of current portion
Long-term portion
Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to the selling costs of future royalties. Used to reflect the noncurrent portion of the liabilities (due after one year or beyond the normal operating cycle, if longer).
Earnings Per Share [Text Block]
Other current assets
Non-cash interest expense related to sale of future royalties
Non-cash interest expense related to sale of future royalties
Non-cash interest expense related to sale of future royalties
Amount of non-cash accounted for as interest expense on liability in relation to the sale of future royalties.
Sale of future royalties
vxrt_DeferredTaxAssetsSaleOfFutureRoyaltyRights
Amount before allowance of valuation allowances of deferred tax asset attributable to deductible temporary differences from the sale of future royalty rights.
vxrt_ProceedsFromSaleOfFutureRoyaltiesNet
Proceeds from Sale of Future Royalties, Net
The cash inflow from the sales of future royalties net pf deferred financing costs.
Royalty Arrangement [Member]
vxrt_ClassOfWarrantOrRightExpirationsInPeriod
Class of Warrant or Right, Expirations in Period (in shares)
Number of warrants for which the right to exercise has lapsed under the terms of the plan agreements.
Property, Plant, and Equipment [Table]
Prepaid clinical and manufacturing expenses
vxrt_PrepaidClinicalAndManufacturingExpenses
Amount of asset related to consideration paid in advance for clinical and manufacturing expenses.
Common stock, par value (in dollars per share)
Common Stock, Par or Stated Value Per Share (in dollars per share)
Basis of Accounting, Policy [Policy Text Block]
Other expense, net
Long-Lived Asset, Class [Axis]
Sale of Stock [Domain]
us-gaap_UnbilledContractsReceivable
Unbilled Contracts Receivable
us-gaap_Assets
Total assets
Investments and Cash
Cash and Cash Equivalents, Policy [Policy Text Block]
Cash and Cash Equivalents, at Carrying Value
us-gaap_CashCashEquivalentsAndShortTermInvestments
Cash, Cash Equivalents, and Short-Term Investments
Other prepaid
Cash [Member]
us-gaap_AllowanceForDoubtfulAccountsReceivable
Accounts Receivable, Allowance for Credit Loss
Common stock reserved for issuance (in shares)
Common Stock, Capital Shares Reserved for Future Issuance (in shares)
us-gaap_DefinedContributionPlanAdministrativeExpenses
Defined Contribution Plan, Administrative Expense
Diluted (in dollars per share)
Diluted (in dollars per share)
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay
us-gaap_ContractWithCustomerLiability
Deferred Revenue, Balance
Deferred Revenue, Balance
Customer [Axis]
The April 2026 ATM [Member]
Related to the April 2026 ATM.
Government Contract [Member]
September 2021 ATM [Member]
Represents September 2021 ATM offering.
Consolidation, Policy [Policy Text Block]
June 2024 Offering [Member]
Represents June 2024 Offering.
LPC ELOC Purchase Agreement [Member]
The ELOC equity purchase agreement with LPC.
LPC [Member]
Represents the company LPC.
us-gaap_InterestReceivable
Interest Receivable
License [Member]
Utah Avenue Lease [Member]
Represents the lease for the Utah Avenue building.
vxrt_IncreaseDecreaseInUnbilledReceivable
Unbilled receivable from government contracts
The increase (decrease) during the reporting period of the amount of revenue for work performed for which billing has not occurred, net of uncollectible accounts.
vxrt_EqupercentOfShareOwnership
EquPercent of Share Ownership
Represents the percent of shares owned.
General and Administrative [Member]
Represents the General and administrative expenses.
vxrt_PercentOfSharePriceForEquityOffering
Percent of Share Price for Equity Offering
The percent of the price per share for the equity offering.
Common Stock Outstanding [Member]
Represents common stock outstanding.
The 2024 ASPR-BARDA Contract [Member]
Represents The 2024 ASPR-BARDA Contract.
Intangible Asset, Finite-Lived [Table Text Block]
The 2024 ATI-RRPV Contract [Member]
Represents The 2024 ATI-RRPV Contract.
vxrt_GovernmentAssistanceAwardAmountInitialAward
Government Assistance, Award Amount, Initial Award
Initial amount of government assistance awarded that comprises amount received, receivable, and to be received unless condition for government assistance is not met. Includes, but is not limited to, government grant, assistance, incentive, award, subsidy, and loan.
Interim Period, Costs Not Allocable [Domain]
Royalty [Member]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Number of RSUs outstanding (in shares)
Number of RSUs outstanding (in shares)
Number of RSUs outstanding, granted (in shares)
Deferred Revenue, by Arrangement, Disclosure [Table Text Block]
September 2021 Lease for Facility in South San Francisco [Member]
Related to September 2021 lease for facility in South San Francisco.
vxrt_PolicyTable
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
Number of RSUs outstanding, forfeite (in shares)
us-gaap_StockholdersEquity
Total stockholders’ equity
Balances
Balances
Forfeited, Weighted average grant date fair value (in dollars per share)
Stock, Class of Stock [Table]
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Domain]
us-gaap_PaymentsForLegalSettlements
Payments for Legal Settlements
Right-of-use assets, net
Operating Lease, Right-of-Use Asset
Other long-term liabilities
vxrt_CommonStockIncreaseInSharesAuthorized
Common Stock, Increase in Shares Authorized (in shares)
The number of increase in shares authorized of common stock.
ESPP [Member]
Related to ESPP.
Property, Plant, and Equipment [Table Text Block]
us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment
Depreciation on property and equipment
Commitments and contingencies (Note 8)
Change in valuation allowance