The six vaccines and their manufacturers are: CSL Limited, Afluria; GlaxoSmithKline Biologicals, Fluarix; ID Biomedical Corp. of Quebec, FluLaval; MedImmune Vaccines Inc., FluMist; Novartis Vaccines and Diagnostics Limited, Fluvirin, and Sanofi Pasteur Inc., Fluzone.
"This season's vaccines contain three strains of the influenza virus that disease experts expect to be the most likely cause of the flu in the United States," the FDA said in a statement. "Each season's vaccines are modified to reflect the virus strains most likely to be circulating. The closer the match between the circulating strains and the strains in the vaccines, the better the protection."
The FDA changed all three strains for this year's influenza vaccine -- an unusual occurrence, as usually only one or two strains are updated from year to year.
A list of the strains included in the 2008-2009 vaccine is available at http://www.fda.gov/cber/flu/flu2008.htm.