(Vax-Before-Travel News)
The spread of H5N1 influenza (bird flu) in animals with spillover into human populations remains a global health risk.
To address this serious issue, various vaccines have been developed over the past few years.
However, researchers at the University of Maryland School of Medicine’s Center for Vaccine Development and Global Health reported encouraging results yesterday from an innovative early-phase clinical trial that found an experimental intranasal vaccine triggered a broad immune response against multiple strains of H5N1.
The study, funded by a grant from the National Institutes of Allergy and Infectious Diseases, was published in the journal Nature Communications on November 6, 2025, and highlights the potential of mucosal immunization strategies — where vaccines are squirted into the nostrils — to prime immune defenses against diverse influenza strains.
The NanoVax H5 intranasal vaccine was found to be safe and well-tolerated. Notably, only people who received the boosted nasal vaccine showed strong immune “priming”—meaning their immune systems were activated and ready to respond—as revealed later, when they were given a single dose of an intramuscular H5 flu shot.
Even on its own without a booster, the NanoVax H5 intranasal vaccine triggered mucosal and systemic immune defenses —something other intranasal recombinant H5 flu vaccines have not achieved in clinical trials.
“The vaccine also helped the immune system recognize multiple versions of the H5N1 virus, which is key because there are different versions of the virus and they change over time,” said study co-lead author Meagan E. Deming, MD, PhD, Assistant Professor of Medicine at UMSOM, in a press release.
“The use of the adjuvant also suggests this approach might allow for lower doses of the vaccine, which could make our current vaccine stocks available to more people in the event of an outbreak.”
IN February 2025, the U.S. Secretary of Agriculture announced a $1 billion comprehensive strategy to curb highly pathogenic avian influenza outbreaks and protect the U.S. poultry industry, and support vaccine development efforts.