FluMist Quadrivalent, the first and only nasal spray quadrivalent flu vaccine, has been made available for the 2013-2014 flu season by MedImmune, for the active immunization of persons 2 through 49 years of age.  This live, intranasal vaccine helps protect against four influenza strains: two influenza A strains and two influenza B lineages.

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The 2013-2014 influenza season is the first time that quadrivalent influenza vaccines will be available in the United States. Previously, only trivalent influenza vaccines were available, which contained two influenza A strains and one influenza B strain. 

Since 2001, influenza B strains from two different lineages (B/Yamagata and B/Victoria) have co-circulated each influenza season in the United States. Trivalent vaccine formulations rely on predictions of which influenza B strains will be dominant in the upcoming season. 

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However, B strain circulation has been difficult to predict correctly, and in 6 of the last 12 flu seasons, the vaccine B strain did not match the dominant circulating B strain.

FluMist Quadrivalent replaces MedImmune’s trivalent influenza vaccine, FluMist (Influenza Vaccine Live, Intranasal).

For more information visit FluMistQuadrivalent.com/hcp/.