Pandemic Strain Gets Nod For 2010-2011 Flu Vaccine

BETHESDA, MD. — The influenza vaccine for the 2010-2011 influenza season in the United States should include a pandemic 2009 H1N1 strain, instead of one of the two seasonal influenza A strains in the current vaccine, a Food and Drug Administration Advisory Panel recommended.

At a meeting of the FDA's Vaccines and Related Biological Products Advisory Committee, the panel unanimously voted 12 to 0 that the current influenza A(H1N1) strain included in the 2009-2010 seasonal flu vaccine, an A/Brisbane/59/2007 (H1N1)–like virus, should be replaced with a pandemic A(H1N1) vaccine virus, an A/California/7/2009–like virus, the component of the monovalent pandemic vaccine that has been used this season.

Also included in the vaccine should be an A/Perth/16/2009 (H3N2)–like virus and a B/Brisbane/60/2008–like virus (B/Victoria lineage).

The panel's recommendation is based on the finding that the vast majority of influenza A(H1N1) viruses circulating worldwide have been the pandemic strain. At the meeting, Nancy Cox, Ph.D., director of the influenza division, at the Centers for Disease Control and Prevention, Atlanta, told the panel that there has been very little evidence of circulating seasonal A(H1N1) influenza viruses, which “most likely pose a low risk” in the forthcoming season in the northern hemisphere.

The panel meets every year at this time to make preliminary recommendations on the components of the trivalent vaccine for the forthcoming influenza season in the northern hemisphere. It considered information on the strains circulating worldwide as well as recommendations announced by the World Health Organization for the 2010-2011 influenza vaccine.

The panel voted to replace the influenza A(H3N2) strain included in the current vaccine, with a southern hemisphere vaccine virus A/Perth/16/2009 (H3N2)–like virus.