January 30, 2013
Technologically Advanced Flu Vaccine Offers Fast Start-Up, Ample Supply

Meriden, CT—As this year’s challenging influenza season continues, the FDA announced approval of another trivalent flu vaccine that can be produced in larger quantities and with a faster start-up than the formulation now used.

FDA said it has approved Flublok, the first trivalent influenza vaccine made using an insect virus (baculovirus) expression system and recombinant DNA technology, for the prevention of seasonal influenza in adults 18 through 49 years of age.

Flublok does not use the influenza virus or eggs in its production, unlike current flu vaccines, and its 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, according to FDA.

That technology, while new to flu vaccine production, already is used to make FDA-approved vaccines to prevent other infectious diseases.

“This approval represents a technological advance in the manufacturing of an influenza vaccine,” said Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research. “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.”

Currently, Flublok, manufactured by Protein Sciences Corp, of Meriden, CT, 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. As with all influenza vaccines, the FDA will evaluate Flublok annually prior to each flu season. The FDA also will assess the recombinant HA proteins produced in the baculovirus expression system and included in Flublok.

“Flublok is truly a modern vaccine,” said Manon Cox, CEO of Protein Sciences. “We use advanced scientific technology to make just the active ingredient of the vaccine without any other viral components.”

Compared to placebo in a study of about 2,300 participants, Flublok was found to be about 44.6% effective against all circulating influenza strains, not just the strains included in the vaccine. Its safety was evaluated in about 2,500 people receiving the vaccine, and the most commonly reported adverse effects were typical of those for the conventional egg-based, inactivated influenza vaccines: pain at the site of injection, headache, fatigue, and muscle aches.

The FDA cautioned that Flublok has a shelf life of 16 weeks from the date of manufacture, and that health care providers should always check the expiration date before administering the vaccine. It will be available in limited supply for the next few months but widely available for the 2013-14 flu season, according to the manufacturer.

In November, FDA approved Flucelvax, another flu vaccine with a different manufacturing process. While Flucelvax is similar to other flu vaccines, virus strains included in the vaccine are grown in animal cells of mammalian origin instead of in eggs.


U.S. Pharmacist Social Connect