First Quadrivalent Flu Vaccine Approved, Debuts Fall 2013


March 01, 2012

March 1, 2012 — Designed to cover more viral bets, the first quadrivalent vaccine to prevent seasonal influenza received approval yesterday from the US Food and Drug Administration (FDA).

The vaccine, FluMist Quadrivalent (MedImmune), will be available for the 2013-2014 flu season. Administered as a nasal spray like the already-approved trivalent FluMist seasonal vaccine, it contains live but weakened forms of viral strains as opposed to inactive ones. The vaccine is indicated for individuals ages 2 years through 49 years.

All FDA-approved seasonal flu vaccines now on the market consist of 3 strains of influenza virus: 2 of influenza A and 1 of influenza B. FluMist Quadrivalent will contain 2 strains of influenza A and 2 strains of influenza B from the B/Yamagata and B/Victoria lineages. A strain from the B/Yamagata lineage is in the current trivalent seasonal vaccine.

The FDA stated that during a typical flu season, 2 different strains of influenza B may be circulating, or else the strain in circulation may not match the B strain selected for the vaccine. Including a second influenza B strain improves the odds of protecting Americans against whatever is circulating.

The demographic profile of the influenza B virus figured into the FDA's decision.

"Illness caused by influenza B virus affects children, particularly young and school-aged, more than any other population," said Karen Midthun, MD, director of the FDA's Center for Biologics Evaluation and Research, in an agency news release. "A vaccine containing the four virus strains most likely to spread and cause illness during the influenza season offers an additional option to aid in influenza prevention efforts."

The agency said that studies conducted previously for the trivalent FluMist vaccine as well as 3 new clinical studies involving some 4000 children and adults established that FluMist Quadrivalent is safe and effective, with an immune response similar to that of the trivalent version.

Adverse reactions to FluMist Quadrivalent resemble those for FluMist — runny or stuffy nose in both children and adults, and headaches and sore throat in adults.

More information about the FDA's approval of FluMist Quadrivalent is available on the agency's Web site.


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