Vaxart Oral COVID-19 Vax Tablet Shows Promise

By Kristin Brooks | 02.03.21

Phase I study reached primary and secondary endpoints of safety and immunogenicity.

Vaxart, Inc., a clinical-stage biotech developing oral vaccines administered by tablet, announced preliminary data from its Phase 1 study of VXA-CoV2-1 showing that its oral COVID-19 tablet vaccine candidate was generally well-tolerated, and immunogenic as measured by multiple markers of immune response to SARS-CoV-2 antigens.
 
Vaxart designed a vaccine with the potential to be protective not only against the prevalent strain, but also against emerging mutations of the Spike (S) protein, by including both the S and N proteins. Virtually all other COVID-19 vaccines include just the S protein.
 
Preliminary Phase 1 trial results show VXA-CoV2-1 triggered multiple immune responses against SARS-CoV-2 antigens, including:
 
  • CD8+ cytotoxic T-cell response to the viral Spike (S) protein, necessary for long-lasting cross-reactive immunity
  • An increase in plasmablast cell number and an upregulation of the mucosal homing receptor, indicating activation of B cells that will home to the mucosa
  • An increase in proinflammatory Th1 cytokines, responsible for orchestrating the immune response to viral infection
  • IgA responses in serum and/or nasal swab samples in 100% of 2 dose subjects; neutralizing antibodies were not detected in serum and IgG responses were not detected in most subjects.

“Our Phase I results highlight the importance of our differentiated vaccine design, as they suggest VXA-CoV2-1 could have broad activity against existing and future coronavirus strains. These results are timely, as we are seeing the emergence of new variants less responsive to first generation vaccines, thus making potential cross-reactivity another important advantage of next-generation vaccines,” said Andrei Floroiu, Vaxart’s Chief Executive Officer.