What is a key feature of the influenza virus?

The influenza virus is characterized by having an RNA genome and a lipid envelope. This key feature is significant because the RNA genome allows for rapid mutation and variation, which enables the virus to adapt and evade the immune response, making it a challenge for vaccine development. The lipid envelope, derived from the host cell membrane during viral budding, contains essential viral proteins known as glycoproteins (hemagglutinin and neuraminidase) that play critical roles in the virus’s ability to infect host cells and in the immune response to the virus. This combination of an RNA genome and lipid envelope is a defining characteristic of the influenza virus and distinguishes it from other viruses.