FDA Approves MF59 Adjuvanted Flu Vaccine for Adults 65 and Older

The US Food and Drug Administration has approved the first adjuvanted quadrivalent influenza vaccine for adults 65 years and older. The vaccine contains the MF59 adjuvant which can protect older adults against seasonal influenza. The approval was granted to Seqirus.

The newly approved vaccine, Fluad Quadrivalent, uses the same MF59 adjuvant as the Fluad vaccine, but with an additional strain included.

A study in Clinical Infectious Diseases published in December 2019, demonstrated that enhanced flu vaccines can provide better protection for older adults. The MF59-adjuvanted vaccine was 1 of 3 study vaccines which produced a stronger immune response than in the standard vaccine group.

"Adults 65 years and older are at high risk for influenza-related complications each season and it is important to have influenza vaccines to help protect this vulnerable population," Anjana Narain, executive vice president and general manager at Seqirus, said in a statement.

While hospitalization rates are currently higher among children and young adults in the 2019-20 North American flu season, the highest rate of hospitalization this flu season has still been observed in adults aged 65 years and older.

Fluad and Fluad Quadrivalent are inactivated vaccines indicated for immunization against influenza caused by both A and B virus subtypes contained in the vaccine.

In clinical research, the most common adverse reactions associated with Fluad administration were injection site pain (25%) and tenderness (21%). The most common systemic adverse reactions seen in clinical studies were myalgia (15%), fatigue (13%), and headache (13%).

Adverse reactions associated with Fluad Quadrivalent included injection site pain (16.3%), headache (10.8%), and fatigue (10.5%).

"The burden of seasonal influenza among adults 65 and older, remains an important public health concern," Gregg Sylvester, MD, chief medical officer at Seqirus, said in the statement.

While vaccination with a seasonal flu shot is recommended for all people 6 months of age and older, adults over the age of 65 years are at heightened risk for complications from influenza, making vaccination particularly important for this population. Since this population experiences age-related immune decline, vaccines which produce a more robust immune response are a promising step for reducing morbidity and mortality during flu season.

The vaccine was approved under accelerated approval due to the immune response elicited by Fluad and Fluad Quadrivalent.