Influenza replicative cycle
The influenza viruses are endocytosed in the host cell and are uncoated in the cytoplasm. Transcription and replication happens in the host cell nucleus. After the assembly of the viral RNA and protein in the cytoplasm, the new virus buds from the host cell plasma membrane.
Vaccines against the influenza virus constantly need to be renewed, because the virus easily changes its genetic material.
Extra info: Every year the composition of the influenza vaccination is different.
The genetic material of the influenza virus is NOT integrated in the host cell genome.
Extra info: Because influenza viruses are RNA viruses, they are not incorporated into the host DNA genome.