FDA Approves Flu Vaccine Based on Engineered Viruses

The U.S. Food and Drug Administration approved a new seasonal flu vaccine using a technology that engineers flu virus proteins, rather than the traditional methods of growing inactive viruses in eggs. Flublok, developed by Protein Sciences Corp. of Meriden, Connecticut was approved by the FDA for adults age 18 through 49.

Flublok is based on Protein Sciences’ technology that adapts the natural infection process of insect cells. The company says it reengineers baculoviruses — pathogens that attack insects — with recombinant DNA. This process generates hemagglutinin, the influenza virus protein, the active ingredient in inactivated influenza vaccines and essential for entry of the virus into human cells. While this process is new for flu vaccines, FDA says the techniques are used to produce vaccines for other infections.

Flublok contains three recombinant hemagglutinin proteins to help protect against two influenza virus A strains, H1N1 and H3N2, and one influenza virus B strain. Protein Sciences produces commercial scale quantities of Flublok with its engineered baculovirus technology at a plant in Pearl River, New York. In November 2012, the company announced an expansion of the plant, which is expected to employ 150 staff.

Flublok was tested in clinical trials against a placebo with some 4,600 adults, divided about evenly between treatment and control subjects. The agency says Flublok was about 45 percent effective against all circulating influenza strains, not only the strains that matched the strains included in the vaccine.

FDA says Flublok’s safety was tested in a separate trial that showed common adverse effects to be pain at the site of injection, headache, fatigue, and muscle aches, which are typical for conventional egg-based, inactivated influenza vaccines.

Hat tip: FirstWord Pharma

Photo: ZaldyImg/Flickr

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