Novavax's H5N1

Novavax's H5N1 Vaccine Candidate Demonstrates Immunogenicity in Preclinical Study

GAITHERSBURG, Md., Novavax, Inc. today announced preclinical data demonstrating that Novavax's H5N1 avian pandemic influenza vaccine candidate, leveraging Novavax's recombinant, protein-based nanoparticle technology and Matrix-M® adjuvant, induced robust immune responses by either single or two-dose intranasal (IN) or intramuscular (IM) administration in nonhuman primates. Results were published in Nature Communications.

Peer-reviewed data shows Novavax's H5N1 vaccine candidate demonstrated immunogenicity against currently circulating variants following either single or two-dose administration. Potential for single intranasal or intramuscular dose could differentiate Novavax's vaccine as part of pandemic emergency preparedness efforts.

"These preclinical results underscore the promise and potential of our pandemic influenza program as well as the strength of our technology platform and our ability to deliver against our corporate growth strategy," said Ruxandra Draghia-Akli, MD, PhD, Executive Vice President and Head of Research and Development, Novavax.

Results showed that a single dose administered by either IN or IM routes induced neutralizing antibody responses (IN: 1:54; IM: 1:1,160), at or above the 1:40 titer generally considered to be a protective antibody response. The data showed even higher levels of immunity after two doses. These data suggest that even a single IN dose has the potential to provide protective immunity in individuals previously exposed to seasonal influenza either by vaccination or infection. Further, data showed Novavax's H5N1 vaccine candidate elicited broad antibody responses, suggesting the potential to protect against forward-drift variants from currently circulating strains of the H5N1 virus.

H5N1, a highly pathogenic and dynamic avian pandemic influenza virus, is of concern due to its potential to mutate into a strain adapted for sustained human-to-human transmission. To date, there have been 70 confirmed total reported human cases in the U.S., and one death associated with H5N1 avian pandemic influenza infection.1 As of July 2025, no reported cases in the U.S. have been proven to result from human-to-human transmission.

As part of its corporate growth strategy, Novavax is making targeted investments in early-stage development programs to create value. Novavax intends to pursue funding, partnership and licensing opportunities for its H5N1 vaccine candidate.