A new, genetically engineered, insect-virus-based flu vaccine: Hooray!

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Amid the most severe influenza season in more than a decade, the FDA approved a next-generation, insect-based flu vaccine the second version that is not grown in eggs, and will therefore be available in a much shorter time enabling better focus on the type of flu in circulation.

The new vaccine is called FluBlok. The makers of the vaccine, Protein Sciences Corp., said that it is the first vaccine made by injecting flu genes into an insect virus and growing it in caterpillar cells. Consequently, unlike current vaccines, it does not require the whole flu virus grown in chicken eggs for production.

While traditional flu shots made in eggs are safe for the egg-allergic, this will give them another option. (While some press reports called FluBlok the first flu vaccine not incubated in chicken eggs, that honor actually goes to Flucelvax, which is grown in mammalian animal cells and was approved by the FDA in November).

The safety of FluBlok was tested in a study of 2,300 people; side effects occurred at about the same rate as the traditional flu shot, and included muscle aches, headache, fatigue and pain in the area the shot was administered. Serious reactions were rare. It was found to be 44.6 percent effective against all strains of the flu, the FDA reported.

About 150,000 doses of the vaccine have been produced and will be distributed by mid-February to people with egg allergies and others who are unable to receive current flu vaccines. But the vaccine is scheduled to be widely available for the 2013-2014 flu season.

According to a FluBlok press release, the vaccine also does not contain preservatives, including the mercury-containing thimerosal. It is designed to protect against the H1N1, H3N2, both A strains and one B strain of the influenza virus, and is approved for people between ages 18 and 49.

ACSH s Dr. Josh Bloom believes that current methods being used in vaccine research will have a big payoff. He says, The strategy of moving away from the traditional method of growing the vaccine in eggs is the way to go. Methods that employ genetically modified living cells to produce the vaccine are faster and more efficient.

And since these vaccines contain only select pieces of the flu virus, there is no chance of them being infectious (which is virtually impossible, except in rare cases where weakened live viruses are used). It is analogous to dumping an engine, tires, a steering wheel and car chassis in your driveway and expecting it to drive.

It looks like the season for influenza is going to be far more serious than any we ve observed recently, says ACSH s Dr. Elizabeth Whelan. Now there is one less excuse for people to not get the flu shot.