The FDA has approved the first ever, quadrivalent flu vaccine. All flu vaccines in circulation today are trivalent, they protect against two strains of flu, generally to type A and one type B strain. The new vaccine will protect against four strains, two A and two B therefore increasing protection and the probability of the vaccine matching the actual flu strain in circulation. Here is the text of the full FDA Media Release (links added). FDA NEWS RELEASE For Immediate Release: Feb. 29, 2012 Media Inquiries: Rita Chappelle, 301-796-4672, rita.chappelle@fda.hhs.gov Consumer Inquiries: 888-INFO-FDA FDA approves first quadrivalent vaccine to prevent seasonal influenza FluMist Quadrivalent, a ———->FULL ARTICLE