Second thoughts on the flu vaccine
Although millions of people are still struggling to find flu shots before the winter flu season starts, scientists are already debating how best to avoid a repeat of this year's vaccine-supply debacle and also how to be better prepared to fight a long-anticipated worldwide flu pandemic.
This week, 16 vaccine manufacturers and officials from the United States and other countries will meet at the World Health Organization in Geneva to map out a flu pandemic battle plan. Officials are worried that continuing problems with vaccine development and supply will make it hard to fight a global flu pandemic, which erupts every 27 years on average. The last was in 1968.
Winged migration. The U.S. vaccine fiasco, in which almost 50 million doses of flu vaccine, half the nation's usual supply, were thrown out because of bacterial contamination at the factory in Britain, is just the latest example. A virulent strain of bird flu that has killed more than 30 people in Asia, and that showed up last month in eagles smuggled into Belgium, also has infectious disease experts sweating.
Thus the excitement over two papers published online last week by the New England Journal of Medicine , which determined that it's possible to shrink a flu shot to 20 percent to 40 percent of the standard dose and still get as good, if not better, an immune response. The trick is to inject the vaccine into the skin, like a tuberculosis test, instead of injecting it into a muscle. Skin is richly provided with immune system cells that recognize invading microbes and help launch a defense. "You can stretch out the amount of vaccine if you have a pandemic flu situation," says Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. However, the intradermal method hasn't been tested to see if it actually prevents infection, and it hasn't been FDA approved for use, making it of no help with the current shortage. Still, Fauci says, "doctors will read these papers and on their own will use it off label," following a common medical practice of using drugs in ways the FDA has not yet approved.
Scientists also investigated whether annual flu shots help reduce the risk of death in old people, whose weakened immune systems tend to mount a lesser response to vaccines and who account for 90 percent of influenza deaths in the United States. Researchers in the Netherlands were able to use physicians' records from more than 26,000 patients over 65 to determine that getting a flu shot two or more years in a row reduced the risk of death from all causes by 24 percent. By contrast, a patient's first flu shot reduced death risk by just 10 percent. The group's findings were published in the Journal of the American Medical Association .
This story appears in the November 15, 2004 print edition of U.S. News & World Report.
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