Resistant against the flu
Whether it is H1N1, H5N1 or H7N9: The flu virus influenza A exists in many different types as its two coating proteins haemagglutinin (HA) and neuraminidase (NA) can be combined in various ways. Theoretically, more than 100 different pairings are possible. Additionally, the coating proteins themselves can undergo changes. This variability is one of the reasons why the flu vaccination has to be renewed every year…