In a significant setback to global efforts in combating HIV, a trial for an experimental HIV vaccine, conducted across Uganda, Tanzania, and South Africa, has been prematurely terminated. Preliminary data indicated that the vaccine, a part of the broader initiative known as PrEPVacc, would not prove effective in preventing infection, as reported by the trial’s chief investigator.
The latest development deals a blow to ongoing endeavors to discover an efficient vaccine against the virus, which has claimed approximately 40 million lives worldwide. Presently, around 39 million individuals are living with HIV, with the majority of cases concentrated in Africa.
The trial, which commenced in December 2020, enrolled 1,512 healthy adults aged 18–40 and was originally scheduled to conclude in 2024. Pontiano Kaleebu, the chief investigator for the program, revealed to Reuters on Thursday that the independent data and safety monitoring committee recommended halting the trial, stating, “Even if we continue, we will not be able to show that the vaccine can be effective.”
Despite existing drugs that can lower the risk of contracting HIV and treatments to control the virus and prevent AIDS development, experts argue that an HIV vaccine remains a crucial tool in eradicating AIDS as a public health threat.
Led by African researchers with support from various European institutions, including Imperial College London, the trial tested two different combinations of experimental HIV vaccines.
Additionally, it explored a novel form of oral pre-exposure prophylaxis (PrEP), a drug designed to reduce the risk of HIV transmission, assessing its efficacy compared to existing drugs. This aspect of the trial is still ongoing.
Participants, predominantly sourced from high-risk populations such as sex workers, gay men, and fishermen, were involved in the trial.
A statement released on Wednesday by the vaccine trial program emphasized the challenging nature of developing an effective HIV vaccine, as this failed trial represented the only remaining active HIV vaccine efficacy trial globally.
