Note 1 - Organization and Nature of Business	9 Months Ended
Sep. 30, 2025
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	NOTE 1. Organization and Nature of Business General Vaxart Biosciences, Inc. was originally incorporated in California in March 2004, under the name West Coast Biologicals, Inc. The Company changed its name to Vaxart, Inc. (“Private Vaxart”) in July 2007, and reincorporated in the state of Delaware. In February 2018, Private Vaxart completed a business combination with Aviragen Therapeutics, Inc. (“Aviragen”), pursuant to which Aviragen merged with Private Vaxart, with Private Vaxart surviving as a wholly-owned subsidiary of Aviragen (the “Merger”). Pursuant to the terms of the Merger, Aviragen changed its name to Vaxart, Inc. (together with its subsidiaries, the “Company” or “Vaxart”) and Private Vaxart changed its name to Vaxart Biosciences, Inc. In March 2025, the Company entered into an At the Market Offering Agreement (the “March 2025 ATM”) with Citizens JMP Securities, LLC (“Citizens”) and B. Riley Securities, Inc. (“B. Riley” and, together with Citizens, the “Managers”), pursuant to which the Company may offer and sell, from time to time through the Managers, shares of its common stock having an aggregate offering price of up to $50.0 million. The shares will be sold pursuant to an effective registration statement on Form S-3 (Registration Statement No. 333-270671) (the “2023 Shelf Registration Statement”), as previously filed with the U.S. Securities and Exchange Commission (the “SEC”). The Company filed a prospectus supplement, dated March 21, 2025, with the SEC in connection with the offer and sale of the shares under the March 2025 ATM. The Company will pay the Managers a placement fee of up to 3% of the gross sale price from each sale of shares under the March 2025 ATM. During the nine months ended September 30, 2025, 382,700 shares were issued and sold under the March 2025 ATM for gross proceeds of $0.2 million, which, after deducting sales commissions and expenses incurred to date, resulted in net proceeds of $0.1 million. In June 2024, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc., relating to the issuance and sale by the Company in an underwritten registered direct offering of 50,000,000 shares of the Company’s common stock, at a price of $0.80 per share. The gross proceeds to the Company from such offering were $40.0 million, and after deducting the underwriting discounts and commissions and estimated offering expenses payable by the Company, the net proceeds were $37.5 million. In January 2024, the Company entered into a securities purchase agreement (the “2024 Securities Purchase Agreement”) with RA Capital Healthcare Fund, L.P. pursuant to which 15,384,615 shares of the Company's common stock were sold to RA Capital Healthcare Fund, L.P. at an offering price of $0.65 per share pursuant to the 2023 Shelf Registration Statement. The gross proceeds from the 2024 Securities Purchase Agreement were $10.0 million and, after deducting offering expenses, the net proceeds were $9.9 million. The Company’s principal operations are based in South San Francisco, California, and it operates in one reportable segment, which is the discovery and development of oral recombinant protein vaccines, based on its proprietary oral vaccine platform.

Note 1 - Organization and Nature of Business

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

NOTE 1. Organization and Nature of Business

General

Vaxart Biosciences, Inc. was originally incorporated in California in March 2004, under the name West Coast Biologicals, Inc. The Company changed its name to Vaxart, Inc. (“Private Vaxart”) in July 2007, and reincorporated in the state of Delaware. In February 2018, Private Vaxart completed a business combination with Aviragen Therapeutics, Inc. (“Aviragen”), pursuant to which Aviragen merged with Private Vaxart, with Private Vaxart surviving as a wholly-owned subsidiary of Aviragen (the “Merger”). Pursuant to the terms of the Merger, Aviragen changed its name to Vaxart, Inc. (together with its subsidiaries, the “Company” or “Vaxart”) and Private Vaxart changed its name to Vaxart Biosciences, Inc.

In March 2025, the Company entered into an At the Market Offering Agreement (the “March 2025 ATM”) with Citizens JMP Securities, LLC (“Citizens”) and B. Riley Securities, Inc. (“B. Riley” and, together with Citizens, the “Managers”), pursuant to which the Company may offer and sell, from time to time through the Managers, shares of its common stock having an aggregate offering price of up to $50.0 million. The shares will be sold pursuant to an effective registration statement on Form S-3 (Registration Statement No. 333-270671) (the “2023 Shelf Registration Statement”), as previously filed with the U.S. Securities and Exchange Commission (the “SEC”). The Company filed a prospectus supplement, dated March 21, 2025, with the SEC in connection with the offer and sale of the shares under the March 2025 ATM. The Company will pay the Managers a placement fee of up to 3% of the gross sale price from each sale of shares under the March 2025 ATM. During the nine months ended September 30, 2025, 382,700 shares were issued and sold under the March 2025 ATM for gross proceeds of $0.2 million, which, after deducting sales commissions and expenses incurred to date, resulted in net proceeds of $0.1 million.

In June 2024, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc., relating to the issuance and sale by the Company in an underwritten registered direct offering of 50,000,000 shares of the Company’s common stock, at a price of $0.80 per share. The gross proceeds to the Company from such offering were $40.0 million, and after deducting the underwriting discounts and commissions and estimated offering expenses payable by the Company, the net proceeds were $37.5 million.

In January 2024, the Company entered into a securities purchase agreement (the “2024 Securities Purchase Agreement”) with RA Capital Healthcare Fund, L.P. pursuant to which 15,384,615 shares of the Company's common stock were sold to RA Capital Healthcare Fund, L.P. at an offering price of $0.65 per share pursuant to the 2023 Shelf Registration Statement. The gross proceeds from the 2024 Securities Purchase Agreement were $10.0 million and, after deducting offering expenses, the net proceeds were $9.9 million.

The Company’s principal operations are based in South San Francisco, California, and it operates in one reportable segment, which is the discovery and development of oral recombinant protein vaccines, based on its proprietary oral vaccine platform.