Organization and Basis of Presentation	3 Months Ended
Mar. 31, 2018
Disclosure Text Block [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	NOTE 1. Organization and Basis of Presentation 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. On February 13, 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. All of Private Vaxart’s convertible promissory notes and convertible preferred stock was converted into common stock, following which each share of common stock was converted into approximately 0.22148 shares of the Company’s common stock (the “Conversion”). Except as otherwise noted in these Financial Statements, all shares, equity securities and per share amounts of Private Vaxart are presented to give retroactive effect to the Conversion. Immediately following the completion of the Merger, the Company effected a reverse stock split at a ratio of one new share for every eleven shares of the Company’s common stock outstanding (the “Reverse Stock Split”). Except as otherwise noted in these Financial Statements, all share, equity security and per share amounts are presented to give retroactive effect to the Reverse Stock Split. Immediately after the Reverse Stock Split there were approximately 7.1 million shares of the Company’s common stock outstanding. Private Vaxart’s stockholders, warrantholders and optionholders owned approximately 51% of the fully-diluted common stock of the Company, with Aviragen’s stockholders and optionholders immediately prior to the Merger owning approximately 49% of the fully-diluted common stock of the Company. The Company also assumed all of Private Vaxart’s outstanding stock options and warrants with proportionate adjustments to the number of underlying shares and exercise prices based on an exchange ratio, based on the combined impact of the Conversion and the Reverse Stock Split, of approximately 0.0201346 shares of the Company for each share of Private Vaxart. 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, and small-molecule antiviral drugs. Liquidity and Going Concern Since incorporation, the Company has been involved primarily in performing research and development activities, hiring personnel, and raising capital to support these activities. The Company has experienced losses and negative cash flows from operations since its inception. As of March 31, 2018, the Company had an accumulated deficit of $77.7 million and a loan with an outstanding balance of $4.7 million from Oxford Finance, LLC (“Oxford Finance”), repayable in monthly installments by the end of 2020 (see Note 9). The Company expects to incur increasing costs as research and clinical trials are advanced and, therefore, expects to continue to incur losses and negative operating cash flows for the next several years. Absent additional funding or adjustments to currently planned operating activities, and in view of the uncertainties regarding future royalty revenue on sales of Relenza® and Inavir®, management believes that the Company’s cash, cash equivalents and short-term investments, together with funds acquired from Aviragen through the Merger, are only sufficient to fund the Company into the first quarter of 2019. The Company reviews its operations and clinical plans on a continuing basis and has not yet entered into any commitments for its upcoming clinical trials. The Company plans to finance its operations with royalty revenue on sales of Relenza® and Inavir®, additional equity or debt financing arrangements, revenue from its contract with the Department of Health and Human Services, Office of Biomedical Advanced Research and Development Authority (“HHS BARDA”), and potentially with additional funding from government contracts or strategic alliances with partner companies. The availability and amount of such funding is not certain. The uncertainties inherent in the Company’s future operations and in its ability to obtain additional funding raise substantial doubt about its ability to continue as a going concern beyond one year from the date these financial statements are issued. The financial statements do not include any adjustments that might result from the outcome of this uncertainty. While management believes its plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. If adequate funds are not available, the Company may be required to reduce operating expenses, delay or reduce the scope of its product development programs, obtain funds through arrangements with others that may require the Company to relinquish rights to certain of its technologies or products that the Company would otherwise seek to develop or commercialize itself, or cease operations.

NOTE 1. Organization and Basis of Presentation

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.

On February 13, 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. All of Private Vaxart’s convertible promissory notes and convertible preferred stock was converted into common stock, following which each share of common stock was converted into approximately 0.22148 shares of the Company’s common stock (the “Conversion”). Except as otherwise noted in these Financial Statements, all shares, equity securities and per share amounts of Private Vaxart are presented to give retroactive effect to the Conversion.

Immediately following the completion of the Merger, the Company effected a reverse stock split at a ratio of one new share for every eleven shares of the Company’s common stock outstanding (the “Reverse Stock Split”). Except as otherwise noted in these Financial Statements, all share, equity security and per share amounts are presented to give retroactive effect to the Reverse Stock Split.

Immediately after the Reverse Stock Split there were approximately 7.1 million shares of the Company’s common stock outstanding. Private Vaxart’s stockholders, warrantholders and optionholders owned approximately 51% of the fully-diluted common stock of the Company, with Aviragen’s stockholders and optionholders immediately prior to the Merger owning approximately 49% of the fully-diluted common stock of the Company. The Company also assumed all of Private Vaxart’s outstanding stock options and warrants with proportionate adjustments to the number of underlying shares and exercise prices based on an exchange ratio, based on the combined impact of the Conversion and the Reverse Stock Split, of approximately 0.0201346 shares of the Company for each share of Private Vaxart.

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, and small-molecule antiviral drugs.

Liquidity and Going Concern

Since incorporation, the Company has been involved primarily in performing research and development activities, hiring personnel, and raising capital to support these activities. The Company has experienced losses and negative cash flows from operations since its inception. As of March 31, 2018, the Company had an accumulated deficit of $77.7 million and a loan with an outstanding balance of $4.7 million from Oxford Finance, LLC (“Oxford Finance”), repayable in monthly installments by the end of 2020 (see Note 9).

The Company expects to incur increasing costs as research and clinical trials are advanced and, therefore, expects to continue to incur losses and negative operating cash flows for the next several years. Absent additional funding or adjustments to currently planned operating activities, and in view of the uncertainties regarding future royalty revenue on sales of Relenza® and Inavir®, management believes that the Company’s cash, cash equivalents and short-term investments, together with funds acquired from Aviragen through the Merger, are only sufficient to fund the Company into the first quarter of 2019.

The Company reviews its operations and clinical plans on a continuing basis and has not yet entered into any commitments for its upcoming clinical trials. The Company plans to finance its operations with royalty revenue on sales of Relenza® and Inavir®, additional equity or debt financing arrangements, revenue from its contract with the Department of Health and Human Services, Office of Biomedical Advanced Research and Development Authority (“HHS BARDA”), and potentially with additional funding from government contracts or strategic alliances with partner companies. The availability and amount of such funding is not certain.

The uncertainties inherent in the Company’s future operations and in its ability to obtain additional funding raise substantial doubt about its ability to continue as a going concern beyond one year from the date these financial statements are issued. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.

While management believes its plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. If adequate funds are not available, the Company may be required to reduce operating expenses, delay or reduce the scope of its product development programs, obtain funds through arrangements with others that may require the Company to relinquish rights to certain of its technologies or products that the Company would otherwise seek to develop or commercialize itself, or cease operations.