This CDC page about Flu is the Official U.S. Government website for “regular flu” or influenza, avian and pandemic flu information. Defines seasonal flu and other types of flu viruses. Find information to prevent flu; symptoms and diagnosis; vaccination; treatment; who is at higher risk. See FluView for maps and charts that track flu activity weekly across the US. The first two weeks of the 2022-2023 flu season are starting off at higher levels than usual. The site includes a comparison of symptoms between flu and Covid. CDC stands for the Centers for Disease Control and Prevention. Updated December 2022.