VXA-CoV2-3.3

VXA-CoV2-3.3 is an investigational oral tablet vaccine candidate developed by Vaxart for the prevention of COVID-19. It utilizes a non-replicating adenovirus type 5 (Ad5) vector to deliver the gene for the SARS-CoV-2 spike protein, combined with a Toll-like receptor 3 (TLR3) agonist as an adjuvant. Designed to induce both systemic and mucosal immunity, the vaccine aims to provide broader protection and potentially reduce viral transmission compared to injectable vaccines. The program received significant funding from the U.S. Biomedical Advanced Research and Development Authority (BARDA) under Project NextGen for a Phase 2b trial comparing it to authorized mRNA vaccines. However, the trial was subject to a stop work order in August 2025 due to shifts in federal policy. The vaccine is room-temperature stable, facilitating easier global distribution.

Other names

Vaxart oral COVID-19 vaccineVXA-CoV2-3.3 (KP.2 strain)