influenza A virus

Influenza A virus is a type of virus that causes the flu, an infectious respiratory illness. It is highly variable, meaning it can change frequently, which makes it capable of causing seasonal epidemics and occasional pandemics. The virus spreads easily through respiratory droplets when an infected person coughs, sneezes, or talks. Symptoms include fever, cough, body aches, and fatigue. Vaccines are available to help prevent infection, but because of its ability to mutate, new vaccines are needed each flu season. Public health measures like handwashing and social distancing can also help reduce transmission.