FDA approves next-generation influenza vaccine

Hannah Blake

pharmaphorum

A new seasonal influenza vaccine has been approved by the Food and Drug Administration for use in the United States. Developed by Protein Sciences Corp, Flubok is the first trivalent influenza vaccine made using an insect virus (baculovirus) expression system and recombinant DNA technology. Flublok is approved for the prevention of seasonal influenza in people 18 through 49 years of age.

Unlike current flu vaccines, Flublok does not use the influenza virus or eggs in its production. Flublok’s novel manufacturing technology allows for production of large quantities of the influenza virus protein, hemagglutinin (HA) – the active ingredient in all inactivated influenza vaccines that is essential for entry of the virus into cells in the body. The majority of antibodies that prevent influenza virus infection are directed against HA.

While the technology is new to flu vaccine production, it has already been used to make vaccines to prevent other infectious diseases. These vaccines have also been approved by the FDA.

“This approval represents a technological advance in the manufacturing of an influenza vaccine. The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic, because it is not dependent on an egg supply or on availability of the influenza virus.”

Karen Midthun, M.D., director of the FDA’s Center for Biologics Evaluation and Research.

Flublok contains three, full-length, recombinant HA proteins to help protect against two influenza virus A strains, H1N1 and H3N2, and one influenza virus B strain.

The effectiveness of Flublok was evaluated in a clinical trial conducted at various sites in the United States that compared the use of Flublok in about 2,300 people to a placebo that was given to a control group of similar size. Flublok was approximately 44.6% effective against all circulating influenza strains, not just the strains that matched the strains included in the vaccine.