It might seem like little more than a seasonal nuisance these days, but the flu is a massive and potentially deadly health problem for the world to deal with. The virus mutates quickly and unpredictably, making it hard to develop effective vaccines. Now, researchers at Georgia State University have combined two antigens to create a vaccine that protects mice against six different strains of the flu, potentially paving the way for a universal flu vaccine.

Traditionally, flu vaccines are made up of proteins that are found in the influenza virus, training the patient’s immune system what to watch for. The problem is that viruses mutate very quickly, often changing up these proteins and rendering vaccines ineffective. That’s why the flu shot changes every year, and can’t always prevent you from getting sick.

As such, a long-lasting, universal flu vaccine would be a huge help, if scientists can ever nail it. And now, we might be a step closer.

The new vaccine is made up of double-layered nanoparticles that contain two flu virus proteins – matrix protein 2 ectodomain (M2e) and neuraminidase (NA). M2e is common to all flu strains with very little difference between them, and it mutates relatively slowly. NA, meanwhile, is found on the surface of the virus and also changes slower than others. Targeting these proteins should make the vaccines more effective against a wider variety of strains for a longer period of time.

“It’s important to mention that a lot of flu vaccines haven’t focused on NA before,” says Gilbert Gonzalez, co-author of the study. “NA is becoming a more important antigen for influenza vaccine research. Previously, it had been ignored or discounted because hemagglutinin (HA) is much more dominant. When you get a flu infection, your body reacts to the HA.”

To test out the new nanoparticle vaccine, the researchers injected it into groups of mice, then exposed them to one of six flu strains. The vaccine managed to stave off the virus for up to four months after immunization, suggesting that the drug could eventually form the basis of a universal flu vaccine.

“This nanoparticle antigen combination conferred mice with strong cross protection,” says Ye Wang, first author of the study. “It can protect mice from different strains of influenza virus. Each season, we have different flu strains that affect us. By using this approach, we hope this nanoparticle vaccine can protect humans from different strains of influenza virus.”

Of course, the vaccine will need to be tested in humans to make sure the benefits carry across. Eventually, the team plans to try to load the drug onto microneedle patches.

The research was published in the journal Advanced Healthcare Materials.

Source: Georgia State University