The FDA (U.S.) said it approved the 2012-2013 influenza (flu) vaccine formulation for all six manufacturers licensed to produce and distribute the vaccines in the United States. Based on that information and the recommendations of the FDA’s Vaccines and Related Biological Products Advisory Committee, the strains selected for inclusion in the 2012-2013 flu vaccines are:

– A/California/7/2009 (H1N1)-like virus
– A/Victoria/361/2011 (H3N2)-like virus
– B/Wisconsin/1/2010-like virus.

The FDA noted that while the H1N1 virus is the same as what was included in the 2011-2012 influenza vaccines, this year’s influenza H3N2 and B viruses differ from those in the 2011-2012 influenza vaccines. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm315365.htm