Novavax Shares Promising Results For Bird Flu Vaccine, Tested In Primates

Novavax, Inc. (NASDAQ:NVAX) on Thursday revealed preclinical data from the H5N1 avian pandemic influenza vaccine candidate.

Leveraging Novavax’s recombinant, protein-based nanoparticle technology and Matrix-M adjuvant, the vaccine candidate induced robust immune responses in nonhuman primates after either single—or two-dose intranasal (IN) or intramuscular (IM) administration.

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 a protective antibody response.

The data showed even higher levels of immunity after two doses.

These data suggest that even a single IN dose can provide protective immunity in individuals previously exposed to seasonal influenza 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. 

Results were published in Nature Communications. 

H5N1 is a highly pathogenic and virulent avian pandemic influenza virus, commonly referred to as “bird flu.”

There have been 70 confirmed total reported human cases in the U.S., and one death associated with H5N1 avian pandemic influenza infection.

As of July 2025, no reported cases in the U.S. have been proven to result from human-to-human transmission. 

Novavax intends to pursue funding, partnership, and licensing opportunities for its H5N1 vaccine candidate. 

In June, Novavax announced results from the initial cohort of its COVID-19-Influenza Combination (CIC) and standalone trivalent hemagglutinin nanoparticle seasonal influenza (tNIV) Phase 3 trial.

The study showed that the CIC and flu vaccine candidates induced immune responses similar to those of licensed comparators Nuvaxovid and Sanofi SA's (NASDAQ:SNY) Fluzone HD, respectively.

Both standalone flu and CIC vaccine candidates induced robust immune responses to the vaccine strains (2.4-5.7-fold over baseline).

In May, Novavax received limited approval from the U.S. Food and Drug Administration for its COVID-19 vaccine, Nuvaxovid, marking a regulatory milestone and unlocking a $175 million milestone payment from Sanofi.

Price Action: NVAX stock is up 5.61% at $8.28 at the last check on Thursday.

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