FDA panel approves four-strain flu vaccines

A U.S. Food and Drug Administration advisory panel on vaccines gave its approval on Wednesday to quadrivalent, or four-strain, flu vaccines that may over time replace current three-strain vaccines.

The panel gave its endorsement to a proposal by the World Health Organization to use the four-strain vaccines for the next flu season. GlaxoSmithKline and AstraZeneca already have four-strain vaccines approved for use, the Wall Street Journal reports.

The quadrivalent vaccines contain two influenza A strains and two influenza B strains. The panel suggested that the B strain from this season be changed to more effectively match the influenza strains that caused major illness in the U.S. during the current flu season.

By providing four strains, the new vaccines increase the likelihood that health experts and vaccine manufacturers are able to match circulating strains with the ones present in the vaccine.

In December, Glaxo's Fluarix Quadrivalent was approved by the FDA. The December approval followed the approval of MedImmune's FluMist Quadrivalent, which puts four vaccine strains into a mist for patients who dislike needles.

Now that the FDA has endorsed the quadrivalent vaccine, Glaxo and MedImmune will be able to begin taking orders for the new flu season. Sanofi currently has an approval pending for a quadrivalent, but if the vaccine is approved, it may not be ready in time to sell it during the next season, the Wall Street Journal reports.