A federal government website managed by the U.S. Department of Health & Human Services
200 Independence Avenue, S.W. - Washington, D.C. 20201
About the Flu
What are the differences between seasonal flu, H1N1 (swine flu), H3N2v, and H5N1 (avian flu)? In this section you will learn about each of these types of flu.
Seasonal Flu
Learn when to expect seasonal flu, how it spreads, and how to protect yourself. Get information on who tracks cases to provide weekly flu activity reports in the United States.
H3N2v
Get information on H3N2v, how it spreads, who's monitoring it, and how to prevent it.
H1N1 (Swine Flu)
Get information on the status of H1N1 in the United States and how to prevent it. Learn how getting the seasonal flu vaccine is the best protection against H1N1.
H5N1 (Avian/Bird Flu)
Get information on the threat of H5N1, where it exists, and how it is spread. Learn how to avoid H5N1 flu if traveling, and how cases are monitored around the world.