Singapore: The US FDA has approved Sanofi Pasteur supplemental biologics license application (sBLA) for its four-strain influenza vaccine, Fluzone Quadrivalent, which is the newest addition to the Fluzone family. The vaccine is licensed for use in children six months of age and older, adolescents, and adults.

The 2013 influenza season will be the first in which quadrivalent influenza vaccines will be available in the US. Fluzone Quadrivalent vaccine includes two A strains and two B strains to help protect against influenza disease.

Dr David Greenberg, VP, US Scientific and Medical Affairs, Sanofi Pasteur, said that, "Protection against the type B flu strain may be an especially important factor that healthcare providers consider when immunizing children since influenza B causes a substantial number of illnesses, hospitalizations and deaths in the pediatric population."

Each winter the strains for the seasonal influenza vaccines are selected from the influenza strains anticipated to circulate in the Northern Hemisphere during the approaching influenza season. Seasonal influenza vaccines in the US contained only two strains (one strain of type A influenza and one strain of type B influenza) until 1978, when the decision was made to incorporate a second type A influenza strain to help provide protection against both A strains that were co-circulating.

For the past 35 years, influenza vaccines have been trivalent to help protect against three strains of influenza virus: a type A(H1N1), a type A(H3N2) and one type B. However, since the 2001-02 season, two distinct influenza B types (the Victoria and Yamagata lineages) have co-circulated with varying prevalence, making it difficult to predict the next season's dominant B lineage strain. In six of the past 12 seasons, the dominant circulating B strain was from the B-lineage not selected for the vaccine.