GlaxoSmithKline plc [LSE/NYSE: GSK] announced today that the U.S. Food and Drug Administration (FDA) has approved FLUARIX® QUADRIVALENT (Influenza Virus Vaccine) for the immunisation of children (three years and older) and adults to help prevent disease caused by seasonal influenza (flu) virus subtypes A and type 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.