AIDSVAX Study Results to be Publicly Available in Early 2003

The results of VaxGen's three-year AIDSVAX study, the first large-scale clinical trial of an AIDS vaccine, will become public in early 2003, the Chicago Sun-Times reports. Regardless of the results of the study, which enrolled 5,400 volunteers who are at risk for HIV infection, scientists who have been researching an AIDS vaccine for 15 years already know that "[m]aking an effective AIDS vaccine has proved devilishly difficult." Because of HIV's multiple strains and its ability to mutate, scientists "still don't know which parts of the immune system they need to rev up to fight the virus." Even if the trials show that AIDSVAX works, the vaccine "almost certainly" will not be as effective as vaccines for other diseases (Ritter, Chicago Sun-Times, 3/31). "When people say 'vaccine,' they're thinking of something close to 100% efficacious," Peggy Johnston, director of AIDS vaccine research at the National Institute of Allergy and Infectious Diseases, said, adding, "The first (AIDS) vaccines are probably not going to be 100% effective, and I think VaxGen would agree with that" (Abate, San Francisco Chronicle, 4/1). Although most disease vaccines are at least 85% effective, the FDA could approve AIDSVAX even if it is shown to be only 30% effective (Chicago Sun-Times, 3/31). According to VaxGen's Web site, Jonas Salk's polio vaccine was only 60% effective in the beginning, "yet it greatly reduced the rate of infection." VaxGen also notes that studies have shown that an AIDS vaccine that is 30% effective could "dramatically curtail the AIDS epidemic." In addition, if the FDA "snubs" the vaccine, VaxGen may seek its approval in other countries, perhaps the "correct ethical choice" considering high infection rates in developing nations, the San Francisco Chronicle reports (San Francisco Chronicle, 4/1). However, public health officials could "face a vexing situation" with the arrival of an AIDS vaccine that is only 30% to 50% effective. While a vaccine of that level of efficacy could "mark the beginning of the end of the epidemic," it could also give people "a false sense of security," causing them to "feel freer to engage in risky behaviors," such as unprotected sex and needle sharing. "It's a huge issue," Brad Bartholow of the CDC said, adding, "If intensive counseling is not provided and risky behavior increases, it could make things worse." AIDSVAX is also being tested in Europe and Thailand (Chicago Sun-Times, 3/31).