A new sort of flu vaccine that relies on molecular cloning got the U.S. Food and Drug Administration’s seal of approval today. The vaccine, called Flublok, was approved for adults ages 18-49 years old to prevent seasonal flu.
While traditional flu vaccines are produced by influenza eggs or bits of the influenza virus, Flublok is made from an insect virus (baculovirus), molecularly cloned in order to produce large amounts of flu virus protein.
Why does it matter how the vaccine was made? Because doing it this new way means the quantity of flu vaccine produced isn’t dependent on the supply or availability of actual flu virus.
“The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic,” said Karen Midthun, director of the FDA’s Center for Biologics Evaluation and Research.
Bukt despite manufacturing differences, the new vaccine works more or less like the old one. Like traditional influenza vaccinations, the active ingredient is hemaglutinin, a virus protein which the majority of flu-fighting antibodies in us are directed against. Flublok contains three full-length recombinant hemaglutinin proteins, which help protect against two influenza A strains (including H1N1, aka “swine flu,” and H3N2) and one influenza B strain.
In a study comparing the use of Flublok to a placebo, the vaccine was about 44% more effective against all circulating flu strains, not just the strains contained in the vaccine. Common side effects are similar to those for current flu vaccinations, including headache, fatigue and muscle aches.