(Feb.2020 article)The efficacy study, which began in
October 2016, is known as HVTN 702. It enrolled 5407 sexually active, HIV-uninfected men and women between 18 and 35 years of age at 14 sites across the country. Researchers randomly assigned half of the participants to receive a pair of HIV vaccines used in a one-two punch called a prime boost, whereas the other half received placebo shots. The trial was
supposed to last until July 2022. But on 23 January, an independent monitoring board that takes scheduled, sneak peaks at the data to evaluate safety and efficacy, informed Gray and the other leaders of the study that it was “futile” to continue. There were 129 infections in the vaccinated group and 123 in those who received the placebo. “I was catatonic,” Gray says.
No evidence exists that the vaccine caused harm, as happened in a different large HIV vaccine study that was abruptly halted in 2007.