An international team of scientists have discovered a new gene in the flu virus, despite it being 30 years since the flu genome was first decoded. Writing in the journal Science, the researchers found the gene by analysing patterns of genetic change in thousands of different flu strains, including the notorious 1918 Spanish flu.
The new gene, called PA-X, helps to control how the body responds to the virus by damping down the immune response to infection. The discovery is surprising not only because the flu virus has just 12 genes - so finding a new one is a big deal - but also that PA-X seems to reduce the impact of viral infection rather than enhance it.
The scientists think that their finding will help to shed light on why different strains of flu cause more or less severe infections, and could pave the way for future anti-viral treatments.