The initial trial in Africa for two combination vaccines designed to prevent HIV has been terminated due to researchers concluding that the vaccines were not effective.
The pre-exposure prophylaxis vaccine (PrEPVacc) underwent testing on 1,500 individuals aged 18 to 40 in Uganda, Tanzania, and South Africa.
The African-led trial, initiated in December 2020, was halted last month following an interim review of its progress.
The final results are expected to be disclosed in late 2024.
The trials were financed with a €15m grant from the EU’s European & Developing Countries Clinical Trials Partnership.
This setback comes as a blow to hopes of finding a vaccine to prevent HIV infection, particularly in regions like Africa where the virus is widespread.
The trial, known as PrEPVacc, involved over 1,500 participants from three African countries and was aimed at testing two different vaccine combinations.
The decision to stop the trial was made following a review of the data collected so far, which indicated that the vaccines were unlikely to be effective.
Dr. Eugene Ruzagira, trial director from the Uganda Virus Research Institute (UVRI) and assistant professor of epidemiology at the London School of Hygiene & Tropical Medicine, stated, "Vaccinations to PrEPVacc trial participants have been stopped because an analysis of the data collected so far by our independent data-monitoring committee has led them to conclude that there is little or no chance of demonstrating that the vaccines we are testing are reducing the risk of acquiring HIV."
The PrEPVacc trials, led by African researchers with the support of European scientists, assessed two different combinations of HIV to determine if either could prevent infection in populations particularly susceptible to it.
While the PrEPVacc trial's results are disappointing, researchers remain optimistic about the future of HIV vaccine development.
They believe that new approaches and technologies are needed to overcome the challenges posed by this complex virus.
The development of an effective HIV vaccine remains a critical goal, especially in Africa where millions are living with the virus.
Researchers are committed to finding new solutions and ensuring continued progress in HIV prevention efforts.
