CAPE TOWN, SOUTH AFRICA—More than 30 years into the HIV/AIDS pandemic that has claimed an estimated 35 million lives, a preventive vaccine has remained elusive. The only HIV-vaccine clinical trial that has shown potential so far is the United States’ and Thai military’s vaccine, RV144, the results of which were announced in 2009. RV144 demonstrated a “modest” 31 percent efficacy at the end of the three-year study. The vaccine apparently peaked early—it was 60 percent effective at the one-year mark, reported the U.S. Military HIV Research Program. But the effect quickly declined.
The first in a series of trials designed to build on the success of RV144 has now passed a key test in South Africa. A safety trial using the same vaccine regimen from RV 144—but with an added booster shot 12 months afterward—has has shown to be safe for South Africans and demonstrated “robust” immune responses. A successful safety trial was necessary to move forward with extensive clinical research. The research was first presented in late October by South African scientists in Cape Town. Clinical trials of a modified vaccine tailored to Southern Africa will begin in early 2015.
Southern Africa desperately needs such a vaccine. Sub-Saharan Africa is home to two-thirds of all people living with HIV/AIDS and the main driver is unprotected heterosexual sex, according to the Joint United-Nations Program on HIV/AIDS, or UNAIDS. South Africa has the unfortunate distinction of claiming the world’s highest HIV/AIDS burden, with an estimated 6.3 million people living with HIV/AIDS. New infections, called seroconversions, are increasing at about 370,000 per year in that region. That’s about 1,000 new infections every day. About 20 percent of South African adults—that’s one in five people—are living with the virus, reports UNAIDS. Young women are twice as likely to be infected as young men.