New Flu Shot Cracks Egg Problem

The U.S. Food and Drug Administration has approved a new seasonal flu vaccine made using animal cells instead of chicken eggs, a move experts say will cut vaccine production times in the event of an outbreak.

The vaccine, called Flucelvax and made by Novartis, is approved for flu prevention in people 18 and older. The drug manufacturing process is similar to the half-century-old method of growing the vaccine in an egg. But it's faster - meaning Flucelvax production could be quickly ramped up in response to a pandemic.

"This cell-based technology removes hens and roosters and eggs from the vaccine manufacturing process, which means the vaccine could be made more rapidly, and that's a terrific advantage," said Dr. William Schaffner, president of the National Foundation for Infectious Diseases and chairman of preventive medicine at Vanderbilt University Medical Center in Nashville, Tenn. "It also removes any lingering concern about egg allergies."

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Unlike the egg-based method, in which samples of seasonal flu virus are injected into chicken eggs and incubated, cell-based technology combines small amounts of virus with nutrients and cells in large fermenting tanks.

"All the time it takes for chickens and roosters to do their business is cut short by having this stockpile of frozen cells ready to go," said Schaffner, describing how complicated it is to produce eggs while also maintaining sterility. "When you're dealing with chickens and eggs, of course there are rigorous processes to disinfect the eggs to make sure no there's no bacteria. But you avoid all that with cell-based vaccine production because the cells are kept sterile from very beginning."

The vaccine is isolated from the cells and purified, just as it would be in the egg-based method, according to Schaffner.

"Once the vaccine is produced it's just like the old vaccine," he said.

In a clinical trial of about 7,700 people, Flucelvax was 83.8 percent effective in preventing flu compared to a placebo, according to the FDA.

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Cell culture technology has been used for several decades to produce other vaccines in the U.S., according to the FDA. But Flucelvax is the first flu vaccine to be produced using the newer method.

"It's a proven technology, a more modern technology, and now we're applying it to the flu vaccine," said Schaffner. "It means you can get more vaccine in the pipeline and into people more quickly."