The candidate vaccine for the South African study has been adjusted to a new genetic subtype of HIV that is especially common in Africa. 5,400 HIV negative participants aged 18-35 will take part in the study. They will receive a dose of the vaccine (or a placebo) in month 0, 1, 3, 6 and 12 of the study.
If the results of the efficacy study are convincing (scientists are hoping for an efficacy of at least 60%), the holy grail of HIV prevention comes within reach. To date, the results for this candidate vaccine have been promising. Given the high incidence of HIV in epidemic countries a strong HIV vaccine is necessary to stop the epidemic. Results are expected by 2021.