Only remaining HIV vaccine efficacy trial halted in Africa: summary  

What we know

• African researchers investigating the potency of an experimental HIV vaccine in African countries including Uganda, Tanzania and South Africa have halted after shortfalls with preliminary data.
• This is after investigators discovered that the initial data available would not be effective in preventing the viral infection.
• The trial which was led by African researchers with support from various European institutions including Imperial College London forms part of a wider initiative called PrEPVacc and began in December 2020 and was expected to end in 2024.
• The project had 1,512 healthy adults between the ages of 18 and 40 enrolled for the trial which was testing two different combinations of experimental HIV vaccines and a new form of oral pre-exposure prophylaxis (PrEP), a drug that reduces the risk of getting HIV to compare its effectiveness.
• Participants were picked from high-risk populated places with sex workers, gay men and fishermen.

What they said

Chief investigator for the programme, Pontiano Kaleebu told Reuters that the programme was halted upon recommendations from the independent data and safety monitoring committee of the programme that “even if we continue, we will not be able to show that the vaccine can be effective”. A statement released on December 6, 2023, by the vaccine trial programme, said the failure of the trial which was the only remaining active HIV vaccine efficacy trial in the world highlights "how challenging it is to develop an effective HIV vaccine".