Scientists are making significant progress toward a long-sought goal: a universal flu vaccine that could protect against many different strains of influenza with a single shot.
A research team funded by the National Institutes of Health has developed an experimental vaccine using mRNA technology—the same approach used in COVID-19 vaccines. Instead of targeting just a few predicted flu strains, this new method aims to provide broad protection against all known types of the virus.
The key innovation lies in how the vaccine is designed. Researchers created a formulation that includes genetic instructions (mRNA) for a crucial flu protein called hemagglutinin (HA) from all 20 known influenza subtypes. Once delivered into the body, these instructions prompt cells to produce these proteins, training the immune system to recognize and respond to a wide range of flu viruses.
In laboratory tests on mice and ferrets, the vaccine triggered strong and long-lasting immune responses. Vaccinated animals produced antibodies against all included flu strains and were protected even when exposed to different or mismatched viruses. In many cases, they survived infections that proved fatal to unvaccinated animals.
This approach could solve one of the biggest challenges in flu prevention. Traditional seasonal vaccines must be updated every year based on predictions of which strains will circulate—and they don’t always match perfectly. A universal vaccine could eliminate the need for yearly shots and offer better protection against future pandemics.
However, the research is still in early stages. So far, the vaccine has only been tested in animals, and further studies—including human clinical trials—will be needed to confirm its safety and effectiveness.
Still, scientists see strong potential. With the flexibility and speed of mRNA technology, developing a universal flu vaccine may now be more achievable than ever.
