FDA Approves 2008–2009 Flu Vaccines

The US Food and Drug Administration has approved this year’s seasonal influenza vaccines that include new strains of the virus likely to cause the flu in the US during the 2008–2009 season.

The six vaccines 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.

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 US. The FDA changed all three strains for this year’s influenza vaccine-an unusual occurrence, because usually only one or two strains are updated from year to year. Of note, two of the three strains recommended for the US this year are now in use for the southern hemisphere’s 2008 influenza season, which is currently underway.

Every season’s vaccines are modified to reflect the virus strains most likely to be circulating. Each year, experts from the FDA, World Health Organization, US Centers for Disease Control and Prevention (CDC), and other institutions study virus samples and patterns collected throughout the year from around the world in an effort to identify strains that may cause the most illness in the upcoming season. Based on those forecasts, the FDA decides each February on the three strains that manufacturers should include in their vaccines for the US population. This decision is made early in the year so that manufacturers have enough time to produce the new vaccines.

Approval information and specific indications can be found on the FDA’s web site.