FLU

The single best way to protect against the flu is to get vaccinated each year. (A seasonal vaccine will not protect you against 2009 H1N1 flu. This year there also is a 2009 H1N1 flu vaccine.)

Seasonal Flu

• The "flu shot" - An inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. The flu shot is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions.
• The nasal-spray flu vaccine - A vaccine made with live, weakened flu viruses that do not cause the flu (sometimes called LAIV for "live attenuated influenza vaccine" or FluMist®). (FluMist®) is approved for use in healthy* people 2-49 years of age who are not pregnant.
  
  Each seasonal influenza vaccine contains three influenza viruses-one A (H3N2) virus, one regular seasonal A (H1N1) virus (not the 2009 H1N1 virus), and one B virus. The viruses in the vaccine change each year based on international surveillance and scientists' estimations about which types and strains of viruses will circulate in a given year. About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body.
  
  The seasonal flu vaccine will not provide protection against 2009 H1N1 flu.

H1N

• 2009 H1N1 (sometimes called “swine flu”) is a new influenza virus causing illness in people. This new virus was first detected in people in the United States in April 2009. This virus is spreading from person-to-person worldwide, probably in much the same way that regular seasonal influenza viruses spread. On June 11, 2009, the World Health Organization (WHO) signaled that a pandemic of 2009 H1N1 flu was underway. For more info. Visit http://www.cdc.gov/h1n1flu/general_info.htm.