Participants arrived for a group session at a Youth Against AIDS training camp Harare, Zimbabwe, April 13, 2012. The Jesuit AIDS Project was launched in Harare in 1996 to fight the alarmingly high prevalence of HIV/AIDS and now focuses on prevention and youth development, according to organizers. Reuters

A trial of an HIV vaccine will begin in Zimbabwe this year, health officials announced Tuesday. Researchers in the southern African country, which has one of the highest incidences of the deadly virus in the world, say the vaccine to be tested is based on a drug used in Thailand that was found to be at least moderately effective.

"We do not have a vaccine for HIV like we do for polio or measles,” Nyaradzo Mgodi, a doctor with the University of Zimbabwe and University of California San Francisco research program, which is leading the trial, told All Africa. “Due to human nature and behavioral changes, other preventive measures cannot be fully relied on. But a vaccine would be a stop-gap measure against new HIV infections." The trial is scheduled to start in June.

Around 15 percent of Zimbabwe’s population is thought to be living with HIV, among the worst rates worldwide, according to Avert, a global AIDS charity based in Britain. Although new cases have declined significantly over the last decade, falling by about 50 percent since 2001, people with HIV are still highly discriminated against in Zimbabwe. Many people are reluctant to get tested for fear of being stigmatized, and the high cost of health services has deterred people from seeking treatment.

While condom use in Zimbabwe has been on the rise, a shortage of antiretroviral drugs, or ARVs, over the last 10 years has often meant HIV patients’ access to such life-saving treatments has been sporadic, Avert reported. Developing an effective HIV vaccine is seen as the best way to end the global HIV/AIDS epidemic, which claims an estimated 1.5 million lives around the world every year.

Researchers said the vaccine to be tested in Zimbabwe is slightly different from the one used in Thailand’s trial, which took place between October 2003 and July 2006. The Thailand vaccine, RV 144, was modified to include a booster against a sub-strain of the virus found in southern Africa called Clade CHIV.

Trials of RV 144 in Thailand were the first to show promise for developing an HIV vaccine. But it was only about 31 percent effective at lowering HIV infection rates three years after use.