The PrEPVacc HIV prevention study, aimed at evaluating experimental vaccine regimens and a new oral pre-exposure prophylaxis (PrEP) for HIV, has ceased further vaccinations following an independent data monitoring committee's (IDMC) recommendation.
The committee found limited or no possibility of the trial demonstrating vaccine efficacy in preventing HIV acquisition among 1,500 volunteer participants in East and Southern Africa.
While the vaccine component of the study has been stopped, the IDMC recommended the continuation of the oral PrEP trial. All participants will undergo a six-month follow-up period, including HIV testing, additional safety data collection, and referral for ongoing care after the last vaccine injection or the end of the oral PrEP trial, whichever is longer.
The trial, conducted in Masaka, Uganda; Mbeya and Dar es Salaam, Tanzania; and Durban, South Africa, enrolled 13% men and 87% women aged 18-40.
The vaccination halt occurred following an IDMC review of data up to October 2, 2023, leading to a permanent discontinuation on November 22. Trial leaders are actively communicating this decision to participants, local communities, stakeholders, and regulatory and ethics groups.
PrEPVacc, designed by African researchers with support from European scientists, comprises three trials, testing different HIV vaccine combinations and two oral PrEP formulations.
Although vaccinations ceased due to efficacy concerns, the study continues to assess PrEP drugs Descovy ©️ and Truvada ©️ among its predominantly female study population.
Despite the setback, study leaders remain optimistic about future HIV prevention strategies. The full trial results, anticipated in mid-2024, aim to provide valuable insights into potential HIV preventive measures.
While the interim findings cast doubt on this generation of HIV vaccines, researchers remain committed to advancing innovative preventive approaches and developing future leaders in HIV research.