ABSTRACT
Virology Influenza virus genomes have eight negative ssRNA segments, encoding 10 or 11 proteins. Types (A, B or C) of influenza viruses are based on the nature of the internal proteins. Subtypes of type A viruses are based on the nature of the surface glycoproteins, hemagglutinin (H, of which 15 have been described) and neuraminidase (N, nine).
