Even though flu season arrives yearly, certain spots in the U.S. can still end up short on flu vaccines.

That's because the long production process necessitates a set supply and manufacturers can't respond quickly to sudden spikes in demand.

But an experimental new approach may create a flu vaccine that's easier to produce and, possibly, more effective.

Researchers fused a common protein with a part of the flu virus to create a nanoparticle that's better than current flu vaccines at generating a strong immune response in mice.

The protein, called ferritin, is normally used to store iron. Researchers discovered the protein can self-assemble so that twenty-four ferritins form a spherical molecule with a hollow core.

Then they took another protein, this time from the flu virus, called the haemagglutinin or HA. It's on the surface of the virus as spikes. When researchers mixed the ferritin and HA proteins, a new complex formed so the ferritin spherical core possessed eight HA spikes.

This nanoparticle looks a lot like the natural virus. It stimulated the animal immune system to produce flu antibodies that were more than thirty times higher in mice and ten times higher in ferrets compared to the current vaccine.

Even though the vaccine was made using the HA protein from a flu virus in 1999, it could protect against flu strains from 2007. Normally, traditional flu vaccines only work against that year's viral strains.

This suggests the vaccine has the potential to provide multi-year protection against families of flu viral strains. Eventually, this could lead us to a universal flu vaccine.