FDA approves Sanofi's four-strain flu shot

Editor's Note: This article was updated Jun 11 to clarify that GSK's product was the first injectable quadrivalent flu vaccine approved in the United States. CIDRAP News regrets the error.

The US Food and Drug Administration (FDA) has approved Sanofi Pasteur's Fluzone Quadrivalent (four-strain) injectable flu vaccine, the company announced today.

In March 2012 the FDA approved MedImmune's nasal-spray quadrivalent live-attenuated influenza vaccine, and in December the agency made GlaxoSmithKline's (GSK's) Fluarix Quadrivalent the first injectable four-strain flu vaccine approved for use in the United States. Sanofi's product becomes the second approved four-strain flu shot.

Quadrivalent flu vaccines are designed to protect against both influenza B strains that can circulate in any given year. Experts often have a difficult time deciding which lineage—Yamagata or Victoria—to recommend for inclusion in the vaccine each year, because circulation of B strains is unpredictable. In 6 of the past 12 years, the chosen B strain did not match the predominantly circulating strain, Sanofi said in a news release.

Trivalent vaccines contain only one B strain, along with two influenza A strains (in recent years, a 2009 H1N1 strain and an H3N2 strain).

In February the World Health Organization recommended switching next year's vaccine B strain for the Northern Hemisphere, but it will be from the Yamagata lineage, the same as was used in the 2012-13 season's vaccine.

Fluzone Quadrivalent is licensed for anyone 6 months old and older, Sanofi said in today's release. MedImmune's nasal-spray quadrivalent equivalent is licensed for those 2 years to 49 years old, and GSK's quadrivalent vaccine is licensed for people 3 years old and older.

The newly approved vaccine will be available for the coming flu season, Sanofi said in the news release.

"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," said David Greenberg, MD, vice president of US scientific and medical affairs at Sanofi Pasteur, the company's vaccine division.

In February 2012 a study in the Journal of Infectious Diseases pointed out that a substantial number of hospitalizations and deaths in children are caused by influenza B, and that the strains can cause similarly severe disease as influenza A.

See also:

Jun 10 Sanofi Pasteur news release

Fluzone Quadrivalent fact sheet

Fluzone Quadrivalent prescribing information

Mar 1, 2012, CIDRAP News story "FDA clears first quadrivalent flu vaccine"

Dec 17, 2012, GSK press release on Fluarix Quadrivalent

Feb 21 CIDRAP News story "WHO recommends new B strain for next season's flu vaccine"

Feb 1, 2012, CIDRAP News story "Study finds influenza B may be more severe than thought

Newsletter Sign-up

Get CIDRAP news and other free newsletters.

Sign up now»


Unrestricted financial support provided by

Bentson Foundation 3MAccelerate DiagnosticsGilead 
Grant support for ASP provided by

  Become an underwriter»