Potent protection against H5N1 and H7N9 influenza via childhood hemagglutinin imprinting.

摘要: Two zoonotic influenza A viruses (IAV) of global concern, H5N1 and H7N9, exhibit unexplained differences in age distribution human cases. Using data from all known cases these viruses, we show that an individual’s first IAV infection confers lifelong protection against severe disease novel hemagglutinin (HA) subtypes the same phylogenetic group. Statistical modeling shows protective HA imprinting is crucial explanatory factor, it provides 75% 80% death for both H7N9. Our results enable us to predict distributions future pandemics demonstrate a strain’s pandemic potential increases yearly when group-mismatched subtype dominates seasonal circulation. These findings open new frontiers rational risk assessment.