The FDA has granted approval for influenza vaccines from 6 vaccine manufacturers, in preparation for the 2012-2013 flu season.
The H1N1 virus matches what manufacturers included during the last flu season, but the H3N2 and B viruses differ. The virus strains predicted to circulate don't always end up doing so, but even if that is the case the vaccines can still be effective and at least reduce the symptoms of the virus.
“The best way to prevent influenza is by getting vaccinated each year,” said Karen Midthun, director of the FDA’s Center for Biologics Evaluation and Research. “It is especially important to get vaccinated this year because two of the three virus strains used in this season’s influenza vaccines differ from the strains included in last year’s vaccines.”
For more information on influenza vaccines, check out Influenza Congress USA.