What you need to know:
- PrEPVacc is led by African researchers from Entebbe in Uganda at the MRC/UVRI and LSHTM Uganda Research Unit. They are supported by 15 partner organisations, six from Africa, six from Europe, and three from the US. The Sponsor of PrEPVacc is Imperial College London.
Vaccinations with experimental HIV prevention vaccine regimens have been stopped after an independent monitoring committee found that the regimens have “little or no chance” of preventing HIV acquisition, the researchers announced Wednesday evening.
The researchers said in a statement that the trial has been running among 1,500 volunteer participants in Uganda, Tanzania, and South Africa. At enrolment, participants reported behaviours that made them more vulnerable to acquiring HIV. This information was first shared by trial leaders publicly at the International Conference on AIDS and STIs in Africa (ICASA 2023) on Wednesday in Zimbabwe.
The PrEPVacc HIV prevention study which started in Masaka, Uganda in December 2020, involves experimental vaccine regimens and a new form of oral pre-exposure prophylaxis (PrEP).
Dr Eugene Ruzagira, the trial director based at the Medical Research Council / Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine (MRC/UVRI & LSHTM) Uganda Research Unit, said the vaccine trial's full results would be out after June 2024, when the collection of all the trial data is complete.
“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,” he said.
PrEPVacc is led by African researchers from Entebbe in Uganda at the MRC/UVRI and LSHTM Uganda Research Unit. They are supported by 15 partner organisations, six from Africa, six from Europe, and three from the US. The Sponsor of PrEPVacc is Imperial College London.
Behind PrEPVacc are 80 senior scientists, clinicians, social scientists, community liaison specialists and professional support roles, from 15 partner organisations. They have extensive experience working with HIV and other infectious diseases, as well as clinical trials, and specifically in carrying out HIV vaccine and PrEP trials across Europe and sub-Saharan Africa, according to the leaders of the trial.
Prof Pontiano Kaleebu, the Uganda Virus Research Institute (UVRI) director who is the PrEPVacc’s Chief Investigator, said the development of a vaccine preventing HIV is a critical goal for Africa that will not stop because of these findings.
“It is a goal that must have even greater urgency now that no HIV vaccines are being trialled for efficacy anywhere in the world. We have come so far in our HIV prevention journey, but we must look to a new generation of vaccine approaches and technology to take us forward again,” he said.
“We must also look to a new generation of leaders. We set up PrEPVacc to grow our capacity in Africa to do future trials ourselves and to develop those who will lead them here in Africa. Our participants and collaborators should be very proud that PrEPVacc is the largest HIV vaccine efficacy trial to run in East Africa,” he added.
The failure of the vaccine comes about 30 years after another trial for another experimental HIV prevention vaccine in Uganda failed, according to information from the Joint Clinical Research Centre (JCRC) and the National Institutes of Health of the United States. The vaccine that failed in 1990s, JCRC said, was developed in France while the one whose trial was stopped this year had an experimental vaccine candidate made by the Switzerland-based EuroVacc Foundation.
Uganda, like other countries of the world, is racing to end AIDS by 2030 with the prevention of new infections as a critical pillar in attaining the goal. An HIV vaccine, health experts say, would be essential in the fight.
Follow-up of all participants in PrEPVacc will continue for additional safety data collection, HIV testing and referral for ongoing care for six months after the last vaccine injection for all participants or until the end of the oral PrEP trial, whichever is longest. The leaders also revealed in the statement that the independent committee recommended that “the oral PrEP component of the study continue to completion.”