For five decades, billions of arms have been injected with flu shots containing clear liquid drawn from 11-day-old fertilized chicken eggs. Companies inject the eggs with flu strains. The eggs become tiny incubators, brewing viruses that are then killed and bottled in vials. The nation's entire flu vaccine supply is produced that way, including the 48 million shots that Chiron Corp. can't sell this season because of manufacturing problems in England.
With a crisis sparked by the flu-shot shortage, federal health officials are eager for new, more flexible technologies that could produce a vaccine faster and more cheaply, enticing companies to enter a market that others have largely abandoned because of poor profits.
Protein Sciences Corp. grows vaccine in cells extracted from caterpillar ovaries
(Courtesy Of Protein Sciences Corp.)
One idea is gaining traction: Instead of incubating the nation's entire vaccine supply in chicken eggs, regarded by many as an antiquated system too inflexible and time-consuming to respond to pandemics or vaccine shortages like this year's, federal health officials are encouraging several biotech companies to develop cell-based vaccines. Executives at Protein Sciences Corp. think they have just what experts are looking for: a process that grows vaccine in cells extracted from caterpillar ovaries. Before the flu crisis, the Meriden, Conn.-based company was ignored by investors. Not anymore.
"An investor called me and said, 'Hey, I know we haven't returned your calls like 20 times,' " said Daniel D. Adams, Protein Sciences' chief executive. "Is it too late to get in?"
Although health experts and industry leaders caution that research going on at Protein Sciences and other biotech companies may not cut the time and price to produce usable vaccine, they support such efforts as a possible solution to the nation's flu-fighting problem.
"You can't attract new companies to use a technology of the past," said Bill Pierce, spokesman for Health and Human Services Secretary Tommy G. Thompson. "There's a bit of a 'cool' factor at work here."
Cell culture vaccines are a twist on the chicken egg method of vaccine production. Instead of injecting viruses in eggs, scientists infect cells -- drawn from insects, African green monkeys, dogs, or human fetal retinas -- with flu strains or their components. Then they grow the virus using large fermenting vats in manufacturing plants that look like breweries.
"This really is the wave of the future," said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health and a vocal proponent of cell culture vaccines. He said he will soon ask Congress for $100 million to improve the nation's flu vaccine supply, including jump-starting more cell culture research.
"When you walk into a cell culture factory, you see gleaming stainless steel -- glass and steel and computers and very few people," said Noel Barrett, vice president of research and development at Baxter International Inc. of Deerfield, Ill., which has built a cell culture factory in the Czech Republic.
Walking into a chicken egg factory, by contrast, Barrett said, "You see lots of eggs, thousands and thousands of eggs, and lots of people, and you see that these factories are quite old."