Vaxart, Inc.

You should consider the risks and uncertainties described under Item 1A of Part I of our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, which we filed with the Securities and Exchange Commission on March 13, 2026, together with all other information contained or incorporated by reference in this Quarterly Report on Form 10-Q, when evaluating our business and our prospects. There are no material changes to the risk factors set forth in Part I, Item 1A, in our Annual Report on Form 10-K for the year ended December 31, 2025, except as described below.

Currently, a significant portion of the funds to study our COVID vaccine candidate is expected to come from HHS BARDA. If HHS BARDA were to further reduce, eliminate, delay, or object to funding available to us under the 2024 ATI-RRPV Contract, this could have a significant, negative impact on our revenues and cash flows, and we may be forced to suspend or terminate the continued development of the product candidate or obtain alternative sources of funding.

In June 2024, we entered into the 2024 ATI-RRPV Contract with ATI, the Rapid Response Partnership Vehicle’s Consortium Management Firm funded by HHS BARDA. The 2024 ATI-RRPV Contract, as modified and amended to date, provides for a funding ceiling of approximately $460.7 million. Funding has been released pursuant to authorized milestones delineated in a series of contract modifications. Pursuant to Modification No. 6 to the 2024 ATI-RRPV Contract, dated March 10, 2026 (the most recent contract modification), the total amount of funding available for payment under the 2024 ATI-RRPV Contract is approximately $316.0 million.

We anticipate that a significant portion of the funding to further develop our COVID-19 vaccine candidate will come from the remaining amounts to be received under the 2024 ATI-RRPV Contract. The 2024 ATI-RRPV Contract provides that the government has the right to determine whether to fund the continued performance of the study after the initial funding. In the second half of 2024, the Company initiated and completed enrollment of the 400-participant sentinel cohort of its Phase 2b study comparing the Company’s XBB COVID-19 vaccine candidate to an approved mRNA XBB comparator. In January 2025, the independent data safety monitoring board (DSMB) reviewed 30-day sentinel cohort data and recommended the study proceed without modifications. Twelve-month follow-up data from the sentinel cohort is expected in the first half of 2026. In February 2025, ATI issued a stop work order on the 2024 ATI-RRPV Contract. Subsequently, in April 2025, the Company received written notification from ATI lifting the stop work order, permitting the Company to resume incurring costs, participating in meetings, and communicating with the Government and ATI concerning the project award. In May 2025, HHS BARDA approved initiation of dosing in the 10,000-participant main cohort of the Phase 2b study, and the Company announced the first participant dosed later that month.

In August 2025, ATI issued a second stop work order directing the Company to halt further screening and enrollment for the COVID-19 Phase 2b trial under the 2024 ATI-RRPV Contract. As of the August notification date, the Company had enrolled approximately half of the targeted number of participants for the main cohort of the study. On October 8, 2025, ATI issued a Follow-Up Notice confirming BARDA’s intent to stop all ongoing enrollment under the contract while permitting continued follow-up and planned analyses of both the sentinel cohort and the enrolled main study population. Contract funding is currently under review and is likely to be reduced commensurate with the reduced enrollment of approximately 5,000 participants versus the original planned enrollment of 10,000 participants in the main cohort of the Phase 2b study.

Even as we continue to receive funds under the 2024 ATI-RRPV Contract, the terms of the grant may unfavorably change, or the amount of funding may further decrease. If there is any government decision to discontinue funding under the 2024 ATI-RRPV Contract, our revenues and cash flows would be significantly and negatively impacted and we may be forced to seek alternative sources of funding, which may not be available on non-dilutive terms, terms favorable to us, or at all.

There can be no assurance thatDynavax Technologies Corporation, a Sanofi company (“Dynavax”) will continue to perform the obligations under the 2025 License and Collaboration Agreement or that Dynavax will not exercise its right to terminate the agreement.

On February 10, 2026, Sanofi completed its acquisition of Dynavax. As a result of the consummation of the merger, Dynavax became an indirect wholly owned subsidiary of Sanofi. Sanofi’s vaccine portfolio includes multiple influenza vaccines (Fluzone High-Dose, Flublok, Fluzone) and a co-commercialized protein-based COVID-19 vaccine, Nuvaxovid. Sanofi is also developing a combination, single-shot COVID-19/flu vaccine for adults 50+ using Novavax technology, targeting a non-mRNA approach. Sanofi can be expected to make their decision for further investments in our Dynavax partnered COVID-19 vaccine and potentially other Vaxart assets in the context of this larger vaccine portfolio.

Changes in the regulatory environment for vaccines could adversely impact our product development and commercialization efforts.

Recent developments in U.S. vaccine oversight, including increased involvement by the FDA Commissioner’s office in approval decisions and changes to the Advisory Committee on Immunization Practices (ACIP), may create additional uncertainty in the regulatory process. These changes could result in new or heightened requirements for clinical data, slower review timelines, or altered recommendations for use, any of which could adversely affect the timing, likelihood of approval, and market acceptance of our vaccine candidates.

Ourcommon stock has been delisted from The Nasdaq Capital Market. There can therefore be no assurance that it will trade on a national exchange again.

Effective July 8, 2025, Nasdaq suspended trading in our common stock and subsequently informed the Company on September 19, 2025, that the Company’s common stock will be delisted from The Nasdaq Capital Market due to the Company’s ongoing failure to comply with the minimum bid price requirement under Nasdaq Listing Rule 5550(a)(2). Vaxart, Inc. was formally delisted from Nasdaq following a final determination by the Nasdaq's Listing Qualifications Department on November 3, 2025. Our common stock is currently quoted on the OTCQX under the ticker symbol “VXRT.” We can provide no assurance that our common stock will continue to trade on this market, whether broker-dealers will continue to provide public quotes for our common stock, and whether the trading volume of our common stock will be sufficient to provide for an efficient trading market in the future. Stocks trading in the OTC Markets generally have substantially less liquidity, hence, decreasing our ability to issue additional securities or obtain additional financing. The National Securities Markets Improvement Act of 1996, which is a federal statute, prevents or preempts the states from regulating the sale of certain securities, which are referred to as “covered securities.” If we are no longer listed on Nasdaq, our securities would not qualify as covered securities under the statute and we would be subject to regulation in each state in which we offer our securities.

We may not be able to retain coverage by securities or industry analysts because our common stock is not traded on a national securities exchange.

The trading in our common stock is influenced by independent research and reports that securities or industry analysts publish about us or our business from time to time. Because our common stock trades on the OTCQX Best Market rather than a national securities exchange, our exposure to media and coverage by securities and industry analysts may be limited. Further, if one or more of the analysts who cover us should downgrade our shares or change their opinion of our business prospects, our share price may be adversely impacted.

We may be unable to realize the potential benefits of our collaboration with Dynavax.

On November 4, 2025, we entered into the License Agreement with Dynavax, pursuant to which we have granted Dynavax an exclusive, worldwide license to develop and commercialize our investigational oral vaccine candidate for COVID-19 based on our oral delivery platform for COVID Indications. On February 10, 2026, Sanofi completed its acquisition of Dynavax. As a result of the consummation of the merger, Dynavax became an indirect wholly owned subsidiary of Sanofi.

Under the License Agreement, we have agreed to, among other things, continue to develop our oral pill COVID-19 vaccine candidate through completion of the ongoing Phase 2b clinical trial of such vaccine candidate. Following a planned for end-of-Phase 2 meeting (“EOP2 Meeting”) with the FDA, Dynavax will have the choice, in its sole discretion, to assume responsibility for the continued development of the vaccine candidate. If Dynavax elects to undertake the continued development of our oral pill COVID-19 vaccine candidate, then we will be entitled to receive from Dynavax a fee of $50 million, subject to the terms and conditions of the License Agreement. The License Agreement further contemplates specific milestone payments payable by Dynavax to us, subject to the terms and conditions of the License Agreement. If Dynavax does not elect to assume responsibility for such continued development of the vaccine candidate, then the License Agreement will terminate pursuant to its terms.

There can be no guarantee that the collaboration with Dynavax will be successful, and we may be unable to realize in full or in part the potential benefits of such collaboration if the results of the Phase 2b clinical trial and EOP2 Meeting are unfavorable or Dynavax does not elect to assume responsibility for the continued development of our oral pill COVID-19 vaccine candidate. Even if Dynavax elects to assume responsibility for such continued development, our collaboration with Dynavax may not result in the successful development or commercialization of products or product candidates in light of the following risks: