FDA Approves Fluzone High-Dose Quadrivalent Influenza Vaccine for Older Adults

The US Food and Drug Administration (FDA) has approved Sanofi’s Fluzone High-Dose Quadrivalent (Influenza Vaccine) for use in adults 65 years of age and older. The vaccine will be made available for the 2020-2021 influenza season.

The approval of the supplemental Biologics License Application marks a transition from the company’s trivalent influenza vaccine first approved in 2009 that contained 2 influenza A strains and 1 influenza B strain. Fluzone High-Dose Quadrivalent contains an additional influenza B strain.

In a phase 3 immunogenicity and safety trial, the quadrivalent vaccine met its primary end point of non-inferior immunogenicity compared with 2 trivalent formulations of Fluzone High-Dose. Additionally, each B strain in Fluzone High-Dose Quadrivalent induced a superior immune response compared with the trivalent formulation.

In a randomized controlled trial evaluating nearly 32,000 adults 65 years of age and older over 2 influenza seasons in the US and Canada, Fluzone High-Dose prevented 24 percent more cases of influenza caused by any circulating influenza strain and 51 percent more cases of influenza caused by strains similar to those contained in the vaccine compared to Fluzone.

"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 US and anticipate approval in the European Union next spring."

Rates of reactions following immunization were similar between the Fluzone High-Dose Quadrivalent and the trivalent formulations. Recipients reported injection-site pain (41.3 percent), myalgia (22.7 percent), headache (14.4 percent), and malaise (13.2 percent), with onset occurring within the first 3 days of vaccination and symptoms resolving within 3 days post-vaccination.