Researchers have launched a clinical trial in South Africa--dubbed HVTN 100--to evaluate a candidate HIV vaccine regimen for safety and the immune response it triggers. The regimen is based on one tested in the U.S. Military HIV Research Program-led RV144 clinical trial in Thailand, which was the first study to demonstrate that a vaccine can guard against HIV infection. Results from the current trial--expected in two years--will help determine whether to take the vaccine regimen into a large-scale study. Report