|Description:||Produced by the National Institute of Allergy and Infectious Diseases (NIAID), this digitally-colorized transmission electron microscopic (TEM) image depicts a small grouping of H1N1 influenza virus particles. Please see the Flickr link below for additional NIAID photomicrographs of various microbes.|
Influenza (flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness. Serious outcomes of flu infection can result in hospitalization or death. Some people, such as older people, young children, and people with certain health conditions, are at high risk for serious flu complications. The best way to prevent the flu is by getting vaccinated each year.
The upcoming season's flu vaccine will protect against the influenza viruses that research indicates will be most common during the season. This includes an influenza A (H1N1) virus, an influenza A (H3N2) virus, and one or two influenza B viruses, depending on the flu vaccine.