FDA approves Sanofi's quadrivalent flu vaccine

The FDA today approved an intradermal quadrivalent influenza vaccine containing two influenza A and two influenza B strains, according to a press release from the manufacturer.

The Fluzone Intradermal Quadrivalent vaccine (Sanofi Pasteur) has been available in trivalent formulation for the past 3 years. It is indicated for adults aged 18 to 64 years for active immunization and prevention of influenza caused by influenza A subtype viruses and type B viruses.

“Influenza B is a common cause of influenza-related morbidity and mortality across all age groups,” David P. Greenberg, MD, vice president of scientific and medical affairs and chief medical officer of Sanofi Pasteur US, said in the press release. “Fluzone Intradermal Quadrivalent vaccine will offer another influenza vaccination option for health care providers and their adult patients with broad coverage against influenza viruses that may be predominant, coupled with the efficiency of using the intradermal microinjection system.”

According to study data, influenza B accounts for 20% to 25% of circulating influenza strains. Tetravalent vaccines provide coverage against only one B virus, and the co-circulation of two predominant lineages of influenza B — Victoria and Yamagata — have made it challenging for experts to select which of these to include in the vaccine. According to the CDC, influenza B strains included in vaccines did not match the predominant B strain in circulation for approximately half of the influenza seasons during 2001-2013.

The FDA’s approval was based on data from a phase 3 clinical study of 3,355 adults who were administered the quadrivalent vaccine or one of two trivalent intradermal controls using strains from either of the two influenza B lineages. Antibody responses to all four strains in the quadrivalent formulation were found to be noninferior to those resulting from the respective strains contained in the trivalent vaccines. The quadrivalent vaccine also had a favorable safety profile. The most common adverse events were pain, pruritus, erythema, swelling and induration at the injection site. Myalgia, headache and malaise were also observed.

The CDC has not expressed a preference for any influenza vaccines this season with the exception of a nasal spray vaccine for healthy children aged 2 to 8 years, provided the nasal spray vaccine is immediately available and the child has no contraindications or precautions to that vaccine.