A study in Africa testing two combined vaccines to prevent HIV has been stopped after scientists determined it was ineffective.
The PrEPVacc, a vaccine for pre-exposure prophylaxis, was undergoing testing on a sample of 1,500 individuals between the ages of 18 and 40 in Uganda, Tanzania, and South Africa.
The trial, led by individuals from Africa, commenced in December 2020 and was halted last month following an interim evaluation of advancement. The conclusive outcomes are anticipated to be disclosed in late 2024.
According to Dr Eugene Ruzagira, who is the trial director at the Uganda Virus Research Institute (UVRI) and an assistant professor of epidemiology at the London School of Hygiene & Tropical Medicine, vaccinations for participants in the PrEPVacc trial have been halted. This decision was made after the independent data-monitoring committee analyzed the data collected so far and determined that there is minimal or no evidence to support the idea that the vaccines being tested can effectively lower the risk of acquiring HIV.
The PrEPVacc experiments, conducted by African scientists with assistance from European researchers, examined two distinct combinations of HIV in order to determine if either could effectively prevent infection in populations with a high risk of contracting the virus. The funding for these trials was provided through a grant of €15m (£12.8m) from the European Union’s European & Developing Countries Clinical Trials Partnership.
Professor Jonathan Weber, a sponsor of the trial from Imperial College London, stated that clinical trials are conducted to find answers to unknown questions. It was crucial to determine if the vaccine regimens used in the PrEPVacc, which have been in development for 20 years, should be eliminated or further explored for their effectiveness in preventing HIV.
He stated that until we receive the final results and analysis for each product, our interim findings indicate that this potential generation of HIV vaccines is not successful.
Earlier attempts in South Africa to evaluate the sole effective vaccine for preventing HIV – the RV144, which was developed in Thailand – were halted in February 2020 due to interim findings indicating its ineffectiveness.
According to UVRI’s chief investigator, Prof Pontiano Kaleebu, the development of a successful HIV vaccine is a crucial objective for Africa.
He stated that this objective is now even more pressing, as there are currently no HIV vaccines being tested for effectiveness anywhere in the world.
“We have made significant progress in our efforts to prevent HIV, but we must now turn our attention to innovative vaccine techniques and advancements in technology to continue moving forward.”
There are approximately 39 million individuals globally who have HIV, with over 25 million residing in sub-Saharan Africa.
Ruzagira expressed optimism during an Aids conference in Zimbabwe on Wednesday, stating that he believes an HIV vaccine will eventually be developed despite the challenges. He acknowledges that the scientific obstacles are significant, but his hopes remain high.
The RV144 vaccine underwent testing in Thailand from 2003 to 2006 and resulted in a nearly 33% decrease in infection rates after three years.
Source: theguardian.com
