Novavax's H5N1 Vaccine Candidate Demonstrates Immunogenicity in Preclinical Study

• 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 

GAITHERSBURG, Md., July 24, 2025 /PRNewswire/ -- Novavax, Inc. (Nasdaq: NVAX) 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. 

"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. "Our R&D pipeline focuses on delivering assets ready for partnership and prioritizing areas of unmet medical need, including vaccines for avian pandemic influenza, where we see clear potential advantages for our technology compared with other vaccines that are licensed or in development." 

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. 

About Novavax  

Novavax, Inc. (Nasdaq: NVAX) tackles some of the world's most pressing health challenges with its scientific expertise in vaccines and its proven technology platform, including protein-based nanoparticles and its Matrix-M adjuvant. The Company's growth strategy seeks to optimize its existing partnerships and expand access to its proven technology platform via research and development (R&D) innovation, organic portfolio expansion in infectious disease and beyond, and forging new partnerships and collaborations with other companies. Please visit novavax.com and LinkedIn for more information. 

Forward-Looking Statements 

Statements herein relating to the future of Novavax, its operating plans and prospects, its partnerships, and the potential for a single intranasal or intramuscular dose differentiating Novavax's H5N1 vaccine, are forward-looking statements. Novavax cautions that these forward-looking statements are subject to numerous risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. These risks and uncertainties include, without limitation, challenges pursuing additional partnership opportunities; challenges satisfying, alone or together with partners, various safety, efficacy, and product characterization requirements, including those related to process qualification, assay validation and stability testing, necessary to satisfy applicable regulatory authorities; challenges or delays in conducting clinical trials or studies for its product candidates; challenges or delays in obtaining regulatory authorization for its product candidates, including for future COVID-19 variant strain changes, its CIC vaccine candidate, its stand-alone influenza vaccine candidate or other product candidates; manufacturing, distribution or export delays or challenges; Novavax's substantial dependence on Serum Institute of India Pvt. Ltd. and Serum Life Sciences Limited for co-formulation and filling Novavax's COVID-19 vaccine and the impact of any delays or disruptions in their operations; difficulty obtaining scarce raw materials and supplies including for its proprietary adjuvant; resource constraints, including human capital and manufacturing capacity; constraints on Novavax's ability to pursue planned regulatory pathways, alone or with partners; challenges in implementing its global restructuring and cost reduction plan; challenges in obtaining commercial adoption and market acceptance of its updated COVID-19 vaccine or any COVID-19 variant strain containing formulation, or for its CIC vaccine candidate and stand-alone influenza vaccine candidate or other product candidates; challenges meeting contractual requirements under agreements with multiple commercial, governmental, and other entities, including requirements to deliver doses that may require Novavax to refund portions of upfront and other payments previously received or result in reduced future payments pursuant to such agreements and challenges in amending or terminating such agreements; challenges related to the seasonality of vaccinations against COVID-19; challenges related to the demand for vaccinations against COVID-19 or influenza; challenges in identifying and successfully pursuing innovation expansion opportunities; Novavax's expectations as to expenses and cash needs may prove not to be correct for reasons such as changes in plans or actual events being different than its assumptions; and those other risk factors identified in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of Novavax's Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent Quarterly Reports on Form 10-Q, as filed with the Securities and Exchange Commission (SEC). We caution investors not to place considerable reliance on forward-looking statements contained in this press release. You are encouraged to read our filings with the SEC, available at www.sec.gov and www.novavax.com, for a discussion of these and other risks and uncertainties. The forward-looking statements in this press release speak only as of the date of this document, and we undertake no obligation to update or revise any of the statements. Our business is subject to substantial risks and uncertainties, including those referenced above. Investors, potential investors, and others should give careful consideration to these risks and uncertainties.  

Contacts: 

Investors

Luis Sanay, CFA

240-268-2022

[email protected] 

Media

Giovanna Chandler

(844) 264-8571 

[email protected] 

References 

1. U.S. Centers for Disease Control and Prevention. H5 Bird Flu: Current Situation. 2025. Available at: https://www.cdc.gov/bird-flu/situation-summary/index.html 

SOURCE Novavax, Inc.