This segment originally aired Dec. 1, 2016, on VICE News Tonight on HBO.
This fall, researchers in South Africa began the largest clinical trial of a potential HIV/AIDS vaccine ever.
South Africa is home to almost a fifth of the world’s HIV-positive population. “That vicious cycle of the older men who’d infect the young girls, and the young girls would infect their peers, that perpetuates the infection,” Helen Joseph Hospital Dr. Sello Mashamaite told VICE News in Johannesburg, South Africa.
The vaccine trial, known as HVTN 702, could lead to a breakthrough in preventing new cases. Researchers expect that the vaccine will be 50 percent effective, a significant improvement from a 2009 version that was 31 percent effective.
Results from the first 5,400 recipients of the vaccine are expected in late 2020.