Full results of the largest-ever clinical trial of an experimental HIV vaccine confirm that the shots barely work, but any protective effect is groundbreaking and should guide scientists as they try to develop a better vaccine.

Although initial promising outcomes had been questioned as a possible fluke, the complete research from the clinical trial in Thailand suggests that the six-shot, two-vaccine regimen could help certain people avoid contracting HIV, the virus that causes AIDS.

Three doctors from Hawaii—Col. Nelson Michael (Punahou '75), Col. Jerome Kim ('Iolani '77) and Dr. Merlin Ross (Radford '73)—presented the research at a conference in Paris this week, with the work published simultaneously online by the New England Journal of Medicine.

Michael, Kim and Ross run the U.S. Army's HIV research program, which conducted the study with the Thai Ministry of Public Health and other collaborators.

The U.S. Army has long partnered with Thailand and its Royal Army to test vaccines and medicines to protect troops and the general population. Developing an HIV/AIDS vaccine became a priority after HIV infection rates soared in Thailand a decade ago.

The vaccine regimen reported on this week seemed most effective in the first year after it was given. It also may have worked better in Thais at average risk of contracting HIV from heterosexual sex, rather than among people at higher risk, such as homosexual men and intravenous drug users.

Those results open promising avenues for further research, even though the benefits of the vaccine are far too modest for it to be put into widespread use now.

For some scientists not affiliated with the research, the most exciting finding was that a vaccine finally seemed to work at all, on anyone.

“;The bottom line is that those results are real,”; Dr. Alan Bernstein, executive director of the Global HIV Vaccine Enterprise, told The Associated Press. “;We, for the first time, have evidence of protection.”;

Dr. Lawrence Corey of the University of Washington, who heads the international HIV Vaccine Trials Network, agreed, telling the AP: “;I think it is an important study. It redirects the field to look at a different kind of vaccine and different kinds of immune responses”; than have been targeted in the past.

Some 33 million people worldwide are infected with HIV, according to the World Health Organization; more than 7,300 new cases occur daily. Two million people died of AIDS in 2007 worldwide. In the United States that year, 1.2 million people were living with HIV and 22,000 people died of AIDS.

Despite advances in prevention and treatment, controlling the spread of the disease ultimately may depend on developing a safe and effective vaccine. This latest clinical trial, even with its modest results, is a critical step in the right direction.