Microbiology After Dark on Instagram: "The influenza virus infects cells in the respiratory tract, using surface proteins to bind, enter, and replicate inside host cells. Its genome is segmented RNA, which allows genetic material to be reshuffled when different strains infect the same host. This structure is one reason influenza changes so efficiently from year to year. It is also why immunity is often temporary. One of the most important surface proteins is hemagglutinin. It allows the virus to