FDA Approves First Adjuvant-Containing Influenza Vaccine

FDA Approves First Adjuvant-Containing Influenza Vaccine

Last week, the US Food and Drug Administration (FDA) approved a seasonal influenza vaccine – Fluad – which is the first of its kind to contain an adjuvant. The vaccine is intended to prevent influenza in people over the age of 65, and combines three virus strains – one subtype B and two subtype A – in order to confer immunity.

Fluad is manufactured with an emulsion of squalene oil – known as adjuvant MF59 – which is a compound that is naturally found in humans and other animals, as well as plants. The adjuvant goes through a number of purification steps before being added to the vaccine mixture, and acts to heighten the body’s immune response to the vaccine. People 65 years of age and older are highly susceptible to influenza infection; approximately 80 to 90 percent of influenza-related deaths, and 50 to 70 percent of influenza-related hospitalizations occur in people of advanced age, according to statistics from the Centers for Disease Control and Prevention.

“Fluad provides another alternative for a safe and effective influenza vaccine in people 65 years of age and older,” said Dr. Karen Midthun, director of the FDA’s Center for Biologics Evaluation and Research. “Immunizing individuals in this age group is especially important because they bear the greatest burden of severe influenza disease and account for the majority of influenza-related hospitalizations and deaths.”

The safety and immunogenicity – the ability of a substance to generate an antibody response – of Fluad was studied in a clinical trial conducted both in the US, and abroad. Fluad was compared to another trivalent influenza vaccine – Agriflu – that is FDA-approved but contains no adjuvant.

The trial evaluated Fluad and Agriflu in 7,082 trial participants, and the study investigators found that Fluad was successful in inducing antibody levels on par with those induced by Agriflu. The safety of Fluad was investigated in 27,000 people aged 65 years and older, and no safety concerns were reported with Fluad.

Fluad was approved by the FDA using the agency’s accelerated approval process. The pathway allows for quicker-than-normal approval for pharmaceuticals that could have an impact on the treatment of life-threatening diseases. The makers of Fluad – Novartis Vaccines and Diagnostics Limited – will be required to conduct a confirmatory clinical trial in order to prove the clinical benefit of the vaccine.

The US is not the first country to approve the use of Fluad as a seasonal influenza vaccine; the product was approved in Italy over 20 years ago, and is used in 38 countries around the world. Both Fluad and Agriflu are manufactured by Novartis which is based in Cambridge, Massachusetts.