FDA Announces Influenza Vaccine For The Season

New influenza vaccines for the current 2008-2009 season have been approved by the U.S. Food and Drug Administration Tuesday.

The six vaccines cleared this year and their manufacturers are: Afluria from CSL Limited, Fluarix from GlaxoSmithKline Biologicals, FluLaval from ID Biomedical Corporation of Quebec, FluMist from MedImmune Vaccines Inc., Fluvirin from Novartis Vaccines and Diagnostics Limited, and Fluzone from Sanofi Pasteur Inc.

All three strains for this year's vaccine have been changed to tackle the virus strains most likely to be circulating at this time. Two of these three strains are currently in use for the Southern Hemisphere's 2008 influenza season. The FDA’s move to change all three strains for the vaccine is unusual-probably a fall-out of last season’s dismal performance.

Last year’s flu outbreak was the worst in four years; the overall vaccine success rate last year was only about 44 percent, according to the U.S. Centers for Disease Control and Prevention.

"One of the biggest challenges in the fight against influenza is producing new vaccines every year. There is no other instance where new vaccines must be made every year. The approval of flu vaccines is a part of FDA's mission to promote the health of Americans throughout the year," said Jesse L. Goodman, M.D., M.P.H., director of FDA's Center for Biologics Evaluation and Research.

Each year, experts from the FDA, World Health Organization, CDC, and other institutions inspect virus samples and patterns collected all through the year around the world so as to predict which strains are likely to cause the most illness in the upcoming season.

Based on these forecasts and recommendations of its Advisory Committee, the FDA annually pinpoints the three strains that manufacturers should include in their vaccines for the U.S. population. The FDA makes this decision each February to allow enough time to manufacturers for production of the new vaccines.

A study published in the April 17 issue of Science did away with much of the uncertainty involved in this process. Researchers charted the origin of flu viruses in East and Southeast Asia, and showed that it would take about eight to nine months for these new viruses to land in west Europe and North America.

Through better surveillance of the emerging flu viruses in these sites of origin, more effective and better-matched vaccines can be produced, the study had said.

Vaccination is the main prevention against influenza, a virus-borne, contagious, respiratory illness. According to the CDC, 5 to 20 percent of the U.S. population suffers from the flu each year. The aged, young children, and people with certain health conditions are more vulnerable to serious flu complications.