FDA approves vaccine formulation for 2012-2013 influenza season

FDA has approved the influenza (flu) vaccine formulation for six manufacturers for the 2012-2013 influenza season.

Each year experts from FDA, the World Health Organization, the Centers for Disease Control and Prevention (CDC), and other public health experts study influenza virus samples and global disease patterns to identify virus strains likely to cause the most illness during the upcoming flu season. Based on that information and the recommendations of FDA’s Vaccines and Related Biological Products Advisory Committee, the strains selected for inclusion in the 2012-2013 flu vaccines are:

• A/California/7/2009 (H1N1)-like virus
• A/Victoria/361/2011 (H3N2)-like virus
• B/Wisconsin/1/2010-like virus

The manufacturers licensed to produce the nation’s 2012-2013 flu vaccines and the related vaccine brand names are CSL Limited (Afluria); GlaxoSmithKline Biologicals (Fluarix); ID Biomedical Corp. (FluLaval); MedImmune Vaccines (FluMist); Novartis Vaccines and Diagnostics Limited (Fluvirin); and Sanofi Pasteur (Fluzone, Fluzone High-Dose, and Fluzone Intradermal).

While the H1N1 virus is the same as the material included in the 2011-2012 influenza vaccines, this year’s influenza H3N2 and B viruses differ from those in the 2011-2012 influenza vaccines. This year’s seasonal vaccines will provide protection against the three influenza virus strains that global surveillance indicates are likely to be the most common strains circulating during the upcoming season.

There is always the possibility of a less than optimal match between the virus strains predicted to circulate and the virus strains that end up causing the most illness. However, even if the vaccine and the circulating strains are not an exact match, the vaccine may reduce the severity of the illness or may help prevent influenza-related complications.

“The best way to prevent influenza is by getting vaccinated each year,” said Karen Midthun, MD, director of FDA’s Center for Biologics Evaluation and Research. “It is especially important to get vaccinated this year because two of the three virus strains used in this season’s influenza vaccines differ from the strains included in last year’s vaccines.”

According to CDC, between 5% and 20% of the U.S. population develops influenza each year. This leads to more than 200,000 hospitalizations from related complications. Influenza seasons are unpredictable and can be severe, with annual influenza-related deaths ranging from a low of about 3,000 to a high of 49,000 people in the United States. CDC’s Advisory Committee on Immunization Practices recommends that all persons 6 months of age and older receive an annual influenza vaccine.

"FDA has approved the influenza vaccine for the 2012-2013 season based on recommendations from various public health groups," said Formulary advisor James M. Wooten, PharmD, associate professor, department of medicine, section of clinical pharmacology, University of Missouri-Kansas City. "Essentially, each year these groups hypothesize what they believe is the most likely virus combination that will cause the most common influenza infection for any given year. As with all hypotheses, sometimes it is correct and sometimes it is not. Generally, FDA and these other groups do an excellent job of predicting."