South Africa continues to be the global epicentre of the HIV epidemic, with approximately eight million people living with the virus —the highest number in the world. While antiretroviral therapy has helped many manage the condition, the scale of the crisis remains severe. Around 20% of South African adults are HIV positive. In 2024, the country recorded about 170,000 new infections and 53,000 AIDS-related deaths.

This trial, known as the HVTN 702 trial, builds on the RV144 trial conducted in Thailand in 2003—the only HIV vaccine trial to have shown any efficacy. Unlike the Thai study, which targeted the Clade B strain, South African scientists have tailored the new vaccine to target Clade C, which is the dominant strain in the country.

The vaccine involves a combination of DNA vaccines to stimulate the body’s immune system, followed by protein injections to enhance the response. 

Dr Danielle Crida, senior medical officer at the Desmond Tutu HIV Foundation, said: “We are following by giving a boost at 12 months, so we are hoping that it will be more effective than the Thai vaccine.” Researchers are aiming for an efficacy rate between 50 and 60%.

The trial is being led by the BRILLIANT Consortium, which comprises the South African Medical Research Council, scientists from Wits University, and the Desmond Tutu HIV Foundation. The consortium also includes scientists from Nigeria, Uganda, Kenya, Tanzania, Zimbabwe, Zambia, and Mozambique. Its objective is to develop an HIV vaccine tailored for African populations.

In a statement, the South African Medical Research Council said: “The trial is…marking a major milestone in African-led HIV vaccine research. Brilliant 011 brings renewed hope that an HIV vaccine developed through African science, for African populations, is becoming increasingly possible.”

Glenda Grey of Wits University described the trial as a “critical step in the long journey toward an effective HIV vaccine.” She said a successful vaccine would “dramatically reduce new infections and ease the long-term financial and logistical pressures of lifelong treatment.”

The launch of this trial comes amid challenges in South Africa’s healthcare system due to international funding cuts, including reductions from the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) and USAID. These funding shifts have previously disrupted local prevention and treatment programmes.