FDA OKs Flu Vaccines for 2008-09 Season

TUESDAY, Aug. 5 (HealthDay News) -- With the memory of last season's flu vaccine mismatch still fresh, U.S. health officials announced Tuesday that they have approved vaccines for the 2008-09 season that include new strains of the virus most likely to circulate.

The U.S. Food and Drug Administration said it changed all three strains for this year's vaccine, which officials called an "unusual occurrence." Typically, just one or two strains are updated year to year. Two of the three strains recommended for the United States this year are now in use for the Southern Hemisphere's 2008 flu season, which is under way.

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"One of the biggest challenges in the fight against influenza is producing new vaccines every year," Dr. Jesse L. Goodman, director of FDA's Center for Biologics Evaluation and Research, said in a news release. "There is no other instance where new vaccines must be made every year."

Each season's vaccines are altered to anticipate the virus strains most likely to be circulating. The closer the match between the circulating strains and the strains in the flu shots, the better the protection, officials said.

To puzzle out the best potential match, officials from the FDA, the U.S. Centers for Disease Control and Prevention, the World Health Organization and other institutions study virus samples and patterns collected throughout the year from around the world. Based on those forecasts, the FDA decides on the three strains that manufacturers should include in their vaccines for Americans.

The six vaccines for the 2008-09 season and their manufacturers are: CSL Limited, Afluria; GlaxoSmithKline Biologicals, Fluarix; ID Biomedical Corporation of Quebec, FluLaval; MedImmune Vaccines Inc., FluMist; Novartis Vaccines and Diagnostics Limited, Fluvirin; and Sanofi Pasteur Inc., Fluzone.

They are designed to protect against A/Brisbane/59/2007 (H1N1)-like virus; an A/Brisbane/10/2007 (H3N2)-like virus; and a B/Florida/4/2006-like virus, the FDA said on its Web site.

But, there's always the chance that the scientists' best guesses will fall short, as was the case during the 2007-08 flu season in the United States. Last year's flu season was the worst in four years, due, in part, to a vaccine that wasn't a good match for certain circulating flu strains, U.S. health officials said.