The results are from the largest bird flu vaccine study to date, of 451 healthy adults ages 18 to 64. The study was done last year at three sites the University of Rochester, the University of Maryland, and the University of California at Los Angeles. John Treanor, M.D., professor of medicine and director of Rochester's Vaccine and Treatment Evaluation Unit, was the overall lead investigator.
Each participant received two shots in the arm one month apart. In participants who received the biggest dose of vaccine, two shots of 90 micrograms each, 54 percent had levels of antibodies considered protective against the virus. The percentage of people who were protected decreased as the size of the dose got smaller: 43 percent of people who received two 45-microgram shots, 22 percent of people who received two 15-microgram shots, and 9 percent of people who received two 7.5-microgram shots. Most patients regarded their side effects as mild; the most common side effect was a sore arm, with people who received the largest doses complaining of a sore arm most frequently.
The dose that was most effective, two shots of 90 micrograms each, is several times larger than the conventional flu shot given each year. Depending on the number of strains targeted, a typical flu shot might include 15 to 45 micrograms (15 micrograms for each strain targeted). In addition, since the world is "immunologically nave" to bird flu hardly anyone has been exposed to the virus it's thought that people should receive not just one but two shots, just as infants do when they are vaccinated against "regular" flu for the first
Contact: Tom Rickey
University of Rochester Medical Center