Influenza virus,a member of the Orthomyxoviridae family,is an enveloped RNA virus with a genome in the form of eight segments requiring an RNA dependent RNA polymerase of viral origin for replication.Influenza viruses can escape the long-term neutralizing antibody response in many hosts via ever-changing antigenic shift and antigenic drift resulting from the particular structure of the virus genome and function of its viral proteins.In this paper,the structure of virus,the genome and encoding proteins of vi...