The flu shot is an inactivated vaccine containing a dead strain of the flu virus. It is given with the needle usually in the arm. It is approved for use in people older than 6 months. About 2 weeks after vaccination, antibodies develop in the body. Antibodies are what provide protection against the influenza virus.
The seasonal flu vaccine protects against three influenza viruses that research indicates will be most common during the upcoming season. The CDC states that the 2010/2011 flu vaccine will protect against the H1N1 virus, the H3N2 virus, and an influenza B virus. The viruses chosen are based on surveillance and scientists’ estimations about which strains will circulate in the given year.
