Abstract
This chapter provides information on the structural organization and replication of influenza viruses in infected cells. The role of genes in the manifestation of pathogenicity and the attenuation of influenza viruses is discussed.
Keywords: Attenuation, Cold-adaptation, Drift, Genetic basis of attenuation, Genome structure, Influenza virus, Mutation, Pathogenicity, Polymerase genes, Proteins, Reassortment, Replication, RNA, Shift, Temperature sensitivity.