Material Event (Form 8-K)

On April 20, 2026, Vaxart, Inc. (the "Company") entered into an amendment (the "Amendment") to its lease agreement (the "Utah Avenue Lease") with a landlord (the "Utah Avenue Landlord") relating to certain properties currently leased to the Company that are located on Utah Avenue in South San Francisco, California. Pursuant to the Amendment, the Company agreed to lease from the Utah Avenue Landlord two additional suites in an additional building on Utah Avenue with a total of approximately 3,531 rentable square feet of space (the "Additional Leased Space"), effective as of May 14, 2026 (the "Expansion Commencement Date"). The term of the lease of the Additional Leased Space is 36 months from the Expansion Commencement Date, unless earlier terminated pursuant to the terms of the Amendment and the Utah Avenue Lease.

As previously disclosed, in December 2025, the Company entered into a termination agreement (the "Termination Agreement") with another landlord (the "Harbor Way Landlord") in connection with the termination of that certain lease agreement (the "Harbor Way Lease") for certain premises located at 170 Harbor Way, South San Francisco, California 94080 that served as the Company's headquarters. The Harbor Way Lease consists of approximately 24,606 square feet of rentable space. Pursuant to the Termination Agreement, the Company and the Harbor Way Landlord agreed to terminate the Harbor Way Lease effective as of May 15, 2026.