FDA announces changes in flu vaccine

SILVER SPRING, Md. The Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee on Wednesday issued their recommendations for next season’s triumvirate influenza vaccine, making only slight changes as compared to the vaccine for the 2008/2009 season.

Next season's vaccine will protect against the same two Type A strains that are in circulation now. However, for the milder Type B strain, next year's vaccine will be slightly different, replacing a Type B/Florida strain of the virus with a version called Type B/Brisbane.

To date, the Centers for Disease Control and Prevention has antigenically characterized 309 influenza viruses this season, including 194 influenza A (H1), 37 influenza A (H3) and 78 influenza B viruses. All 194 influenza A (H1) viruses are related to the influenza A (H1N1) component of the 2008-09 influenza vaccine (A/Brisbane/59/2007). All 37 influenza A (H3N2) viruses are related to the A (H3N2) vaccine component (A/Brisbane/10/2007). 

Influenza B viruses currently circulating can be divided into two distinct lineages represented by the B/Yamagata/16/88 and B/Victoria/02/87 viruses. Twenty-three influenza B viruses tested belong to the B/Yamagata lineage and are related to the vaccine strain (B/Florida/04/2006). The remaining 55 viruses belong to the B/Victoria lineage and are not related to the vaccine strain.