Still, there are no guarantees. “We should never assume that what we have is going to work,” says Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition in New York City. “We’ve got some very good candidates,” the IAVI's Berkley adds, “and if they work it's going to be about access” for developing countries. “We have to make sure there's going to be the political and financial commitment to drive this effort forward, no matter the results of these trials.”
In the future, researchers hope to find new candidates for antibody vaccines. A few people, when infected with HIV, spontaneously generate antibodies that can fend off the virus for decades. Researchers are studying the structure of these natural molecules. The IAVI established its neutralizing antibody consortium in 2002 to speed the discovery of triggers that would prod the immune system to generate more of them.
After 10 years of research, experts are in a better position to judge their expectations for the future. The consensus: a fully effective AIDS vaccine is a long way off. “There are people who will tell you we will never have a vaccine—I can’t say those people are wrong,” Hammer says. But he adds that “you shouldn’t be in this business if you don’t have some degree of optimism based on the science. The world needs an AIDS vaccine. To give up now is selling the science short.”