论文部分内容阅读
Background: Influenza A(H3N2) virus causes continuing epidemics in the human society since its emergence in 1968, due to its ability to change its antigenicity frequently through rapid mutations and thus escape the host immunity.Epistasis is reported to influence the antigenicity of the influenza virus.It is prevalent in the evolution of influenza A virus, especially for its surface proteins Hemagglutinin (HA) and Neuraminidase (NA).However, it is still unknown to what extent the epistasis contribute to the antigenic evolution of influenza A virus.