The FDA has approved GlaxoSmithKline’s Fluarix Quadrivalent (influenza virus vaccine) for the immunization of adults and children (three years and older) to help prevent disease caused by seasonal influenza virus subtypes A and B contained in the vaccine.

Fluarix Quadrivalent is the first intramuscular vaccine to cover against four influenza strains. Scientists classify the influenza strains that cause seasonal flu as A or B strains. Currently administered trivalent (three-strain) flu vaccines help protect against the two A virus strains most common in humans and the B strain expected to be predominant in a given year. But since the year 2000, two B virus strains (Victoria and Yamagata) have co-circulated to varying degrees each season. Various degrees of mismatch have occurred between the B strain included in trivalent vaccines and the B strain that actually circulated, causing an increased risk of influenza-related morbidity across all age groups—children, adults and the elderly. Fluarix Quadrivalent helps protect against the two A strains and adds coverage against a second B strain.

"Trivalent influenza vaccines have helped protect millions of people against flu, but in six of the last 11 flu seasons, the predominant circulating influenza B strain was not the strain that public health authorities selected," said Dr. Leonard Friedland, vice president and head, vaccines clinical development and medical affairs, North America, GSK. "Fluarix Quadrivalent will help protect individuals against both B strains and from a public-health standpoint, can help decrease the burden of disease."

GSK will make Fluarix Quadrivalent available in time for the 2013-14 flu season and also plans to fulfill orders for its trivalent vaccines. Healthcare providers traditionally order flu vaccines about a year in advance of each flu season.

Fluarix Quadrivalent is not currently approved or licensed in any country outside of the U.S.