November 21st, 2014
The first genetically engineered influenza vaccine was approved by the US Food and Drug Administration. The vaccine, called FluBlok, opens the door to develop the annual flu vaccine using something other than traditional cell culture. The health agency approved the vaccine for people between age 18 and 49. The vaccine manufacturer plans to file for regulatory approval in the EU this year.
FluBlok, made by Protein Sciences Corp., of Meriden, Connecticut, is made by inserting the DNA for a particular protein into the genome of an insect virus. This insect virus can then express the gene for this protein, called hemagglutinin, in mass quantities. Hemagglutinin is one of two proteins that sit on the outer coat of the influenza virus, and is connected to the virus’ ability to invade targeted cells and cause the disease. When you see flu viruses categorized as “H1N1,” or “H3N2”, hemagglutinin is the “H” in that designation.
By using genetic engineering techniques, this new vaccine can sidestep the use of live (but attenuated, we hope) influenza virus to make the doses of vaccine. It also can sidestep the time-consumer, laborious process of growing vaccines in cell culture, which often consisted of growing in eggs (a problem for those who are allergic).
As we discussed a few days ago, the FDA, World Health Organization, US Centers for Disease Control (along with other organizations worldwide) collect data every year to determine the most prevalent version of influenza going around. Armed with this information, the FDA then determines what variant of flu the vaccine should have. This year’s FluBlock contains the FDA-recommended vaccine variants of Type B, and two Type A hemagglutinin proteins: H1N1 and H3N2.
Sometimes, as in the case of the H1N1 swine flu epidemic about two years ago, the vaccine needs to be developed very quickly, which cell culture method (growing the live virus in eggs) wasn’t well suited for. This new recombinant DNA technology could meet emergency needs by making the virus much faster. In addition, since the vaccine only contains the “H” protein and not the virus, nobody can get the flu from the vaccine!
influenza prevention, genetic engineering with humans