Federal officials said it could take till January to produce enough swine flu vaccine to protect every American. Why does it take so long?
Because we rely on half-century-old technology. Scientists first have to decide which flu strains to use in the vaccine—they typically pick three, based on predictions of how the virus will evolve by next year. (It’s still unclear whether they’ll include the swine flu in next year’s seasonal flu vaccine.) They then inject the strains into chicken embryos, wait for them to multiply, and extract them several days later to create a so-called “seed stock.” Then comes testing on lab animals, followed by any necessary adjustments to the stock. (Haste can have a price: During the swine flu outbreak of 1976, 500 people who got vaccinated developed a disease called Guillain-Barré syndrome, and 25 of them died.) Once researchers have finalized the vaccine, they repeat the embryo injection process millions of times. So even if they finalize the vaccine in June, it will take at least until September to produce the first 50 million or so doses. Producing all 600 million doses—enough to give America
