New influenza vaccine shows multiple protections

A new vaccine that combines specific virus-like particles to inactivated virus offered protection against H3N2, H1N1 and H5N1 strains of influenza A in mice according to a report in the Proceedings of the National Academy of Sciences.

The study was lead by Richard Compans of Emory University and his colleagues, Med Page Today reports.

"An inactivated viral vaccine supplemented with M2 virus-like particles provides complete cross-protection against lethal challenge with heterologous and heterosubtypic influenza viruses…and confers long-lived cross protective immunity," the authors wrote in the study, according to Med Page Today.

While all influenza A viruses have M2 on their surfaces, it is not very immunogenic against lethal infection. The authors speculated that by adding the M2 to virus-like particles, the immune system might respond to it more effectively. Adding the particles was found to significantly improve the immune response to M2.

Mice that were given the combination of inactivated viral vaccine and the M2 virus-like particles survived a lethal dose of H3N2 eight weeks after vaccination with no signs of weight loss or disease, while all mice in the control group without a vaccine died, Med Page Today reports. Those mice that received just the vaccine or just the M2 alone survived, though with severe weight loss of as much as 16 percent. Similar results were found with H5N1 and H1N1.

Researchers concluded that the results "provide evidence that supplementing seasonal flu vaccines with M2 vaccine-like particles is a promising approach for overcoming the limitation of strain-specific protection by current vaccines and developing a universal influenza A vaccine," according to Med Page Today.