FDA Approves Flu Vaccine for Older Adults

The US Food and Drug Administration (FDA) is approving a new supplemental Biologics License Application for Fluzone High-Dose Quadrivalent, the first and only influenza vaccine for adults at least 65 years old.

Fluzone High-Dose, developed by Sanofi Pasteur, was first approved by the FDA in 2009 as a trivalent influenza vaccine that included a pair of influenza A strains and an influenza B strain. The new version contains an additional influenza B strain.

"Increasing protection and delivering improved influenza vaccines are critical to public health," David Loew, Sanofi Executive Vice President and head of Sanofi Pasteur, said in a statement. "We are excited to build upon the success of trivalent Fluzone High-Dose with this FDA approval to expand protection for an additional B strain. We have submitted filings with additional regulatory bodies outside the U.S. and anticipate approval in the European Union next spring."

The recent approval represents the final step for Sanofi before they can transition to quadrivalent influenza vaccines in the US during the 2020-2021 influenza season.

The approval was based in part on data from a phase 3 immunogenicity and safety study, where the product achieved the primary endpoint of non-inferior immunogenicity compared to 2 trivalent formulations of Fluzone High-Dose that contained 1 of the 2 influenza B strains recommended in 2017-2018.

In the secondary endpoint of the trial, each B strain induced a superior immune response compared to the trivalent formulation that did not contain the corresponding B strain.

Rates of local and systemic reactions that occurred following immunization with Fluzone High-Dose Quadrivalent were similar to those induced by trivalent formulations of Fluzone High-Dose.

The most common adverse events in the study were injection-site pain (41.3%), myalgia (22.7%), headache (14.4%), and malaise (13.2%).