Each year, the flu vaccine has to be redesigned to account for new mutations. Researchers at MIT and the Ragon Institute of MIT, Mass. General, and Harvard are hoping for a better way.

The problem is that while the vaccine prompts production of antibodies against the flu virus, those antibodies tend to target a viral protein segment that is especially prone to mutation. If the antibodies could bind to the stable protein “stem” instead of its changeable “head,” they could protect against any flu strain, and people wouldn’t need to get new shots year after year. 

The researchers, led by Arup K. Chakra­borty of MIT and Daniel Lingwood of the Ragon Institute, used computational modeling to explore why the immune system focuses on the protein head and whether it can be “trained” to target the stem instead. The result of their work is a vaccine made of nanoparticles coated with flu proteins that do just that. In studies of mice with humanized immune systems, the researchers showed that their vaccine elicits an antibody response to the protein stem, raising possibilities that could finally end the arms race between vaccine designers and the ever-changing virus.

“The reason we’re excited about this work,” says Chakraborty, “is that it is a small step toward developing a flu shot that you just take once, or a few times, and the resulting antibody response is likely to protect against seasonal flu strains and pandemic strains as well.”