ssA landmark study in 2009 found that a vaccine can protect people from HIV infection. The study found that an experimental vaccine was 31.2 percent effective at preventing HIV infection during the 3.5 years after vaccination, and 60 percent effective one year after vaccination.

In May 2016, the National Institute of Allergy and Infectious Disease in the USA (NIAID) announced that following the success of this earlier trial, the study would be continued pending regulatory approval and expanded in South Africa to a larger group to assess whether it is safe, tolerable and effective in South African adults commencing in November 2016.

The success of such a trial would have a significant impact, especially in South Africa where an estimated 11.2 percent of the total population is infected with HIV as of 2015, and more than 6 million people are living with the virus. For adults between 15 and 49, the infection prevalence rate is even higher at 16.6 percent. The current median time from HIV infection to death in South Africa is 10.5 years for men and 11.5 years for women, despite the existence of medicines to support the health of people living with HIV. Thus, preventing new infections is critical.

This new study is called HVTN 702 and will use a variation of the RV144 drug developed by the NIAID for the 2009 trial that had landmark results. The new regimen is designed to provide greater protection against infection and has been adapted to suit the HIV subtype that is most commonly found in southern Africa. All study participants will receive a total of five injections over a one year period, and volunteers will be randomly assigned to receive either the vaccine or a placebo. The aim is to extend the higher level of protection offered at one year across the whole three-year study period.

During the study, the safety of all patients will need to be monitored to ensure a high standard of care for preventing HIV infection. If a patient does become infected during the year of study, they will be referred to local health care providers and provided with the necessary care and treatment.

The NIAID will be responsible for all operational aspects of the trial, which will enrol 5 400 HIV-uninfected men and women between the ages of eighteen and thirty-five, who are at risk of HIV infection. Although the NIAID is responsible for the operational element, the trial is very much a partnership. The HPTN 702 protocol chair will be Glenda Gray, President and CEO of the South African Medical Research Council. Co-chairs are Linda-Gail Bekker (Deputy Director of the Desmond Tutu HIV Centre at UCT) and Fatima Laher (Director of the Perinatal HIV Research Unit at Chris Hani Baragwanath).

The full results from this study will be available in 2020. For more information on the study, the vaccine itself, or the participants, see the Questions and Answers site of the NIAID.