WASHINGTON—For 50 years, flu vaccine has been produced in the same, slow way, by growing the vaccine in chicken eggs. But scientists recently have invented a faster way, using living cells taken from monkeys, dogs, even caterpillars, instead of eggs.
President Bush asked Congress on Tuesday for $2.8 billion to develop such a "cell culture technology." With this new system, enough vaccine could be produced to inoculate every American within six months of the start of a pandemic, the president said.
A cell culture vaccine would be mass-produced in large sealed vats, like those pharmaceutical companies use to make vaccines against polio, rabies, chickenpox, shingles and hepatitis A.
The cell culture system is still being tested in laboratories in the United States, Europe and Japan. It hasn't been approved yet for human use.
"The main advantage of cell culture is the easy scale-up" to mass production, said Shengqiang Li, a vaccine expert at Sciogen Inc., in San Francisco. "Cells multiply very quickly (in vats), so it takes only a short amount of time to make billions of cells available for vaccine production."
"Using a cell culture approach to producing influenza vaccine offers a number of benefits," Bruce Gellin, director of the National Vaccine Program at the Department of Health and Human Services, told a congressional subcommittee last spring.
"Vaccine manufacturers can bypass the step needed to adapt the virus strains to grow in eggs," he said. "In addition, cell culture-based influenza vaccines will help meet surge capacity needs in the event of a pandemic."
To make a cell culture vaccine, scientists rejigger the genes in the deadly H5N1 bird flu virus. The modified virus, now unable to cause infection, is inserted into animal or insect cells. The cells act as little factories, churning out more copies of the virus for use in a vaccine.
Such work is already under way at a number of companies, including Sanofi Pasteur of Swiftwater, Pa.; Protein Sciences Corp. in Meriden, Conn.; Medimmune Inc. in Gaithersburg, Md.; and Chiron Corp. in Emeryville, Calif.
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(c) 2005, Knight Ridder/Tribune Information Services.
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