The Globally Relevant AIDS Vaccine Europe-Africa Trials Partnership (GREAT) is pleased to announce the successful completion of recruitment of all volunteers for the Phase I HIV-CORE 006 HIV vaccine clinical trial at four vaccine sites in Kenya, Uganda and Zambia. The enrolment of the final participants took place today at the KEMRI-Wellcome Trust Research Programme in Kilifi, Kenya at a time when the world has come together to commemorate World AIDS Day.
Since the first vaccinations were administered at the Center for Family Health Research in Zambia (CFHRZ) in Lusaka, Zambia, in August, a total of 88 participants have been enrolled within a four-month period. At the time of writing, the study team is also pleased to report a participant retention rate of 100% and adherence to vaccination and follow-up visits exceeding 95%. The investigators extend their gratitude to all participants for their huge commitment to the success of this trial.
“This milestone stands as a testament to the comprehensive preparations at the participating sites and the effectiveness of the community engagement and recruitment activities,” said Dr. Vincent Muturi-Kioi, medical director, IAVI. “This is truly an impressive achievement in the face of ongoing COVID-19 restrictions in the region.”
The goal of the HIV-CORE 006 is to evaluate the safety, tolerability, and immunogenicity of a novel HIV vaccine candidate, HIVconsvX, a mosaic vaccine targeting a broad range of HIV-1 variants, making it potentially applicable for HIV strains in any geographical region. While most HIV vaccine candidates work by inducing antibodies generated by B-cells, HIVconsvX induces the immune system’s potent, pathogen obliterating T cells, targeting them to highly conserved and therefore vulnerable regions of HIV – an “Achilles heel” common to most HIV variants. (For more information on how the vaccine works see 'The killer T-cell vaccine strategy' below).
“Over the last decade, while the whole HIV vaccine field has almost exclusively focused on antibody-based protection, we continued believing in and developing a vaccine to induce protective killer T cells. HIV-CORE 006 is the first trial to test the HIVconsvX strategy in African countries with the three main African clades – A, C and D.” says Professor Hanke.
The next milestone for the trial will be the completion of the vaccination phase at the end of December 2021. The trial is anticipated to finish at the end of October 2022.
The HIV-CORE 006 team is led by Professor Tomáš Hanke at the Jenner Institute at Oxford University. In addition to Hanke, the trial’s Chief Investigator is Dr. Paola Cicconi at the Jenner Institute at Oxford University and the other principal investigators are Pontiano Kaleebu, M.D., Ph.D. director of MRC/UVRI and LSHTM Uganda Research Unit; Walter Jaoko, M.D., Ph.D., director of KAVI-Institute of Clinical Research (KAVI-ICR); Eduard Sanders, M.D., Ph.D., principal investigator at KEMRI-Wellcome Trust Research Programme; and William Kilembe, M.D., M.Sc., project director of the Center for Family Health Research Zambia (CFHRZ).
This project is part of the EDCTP2 programme supported by the European Union (grant number SRIA2015-1066) coordinated by Professor Tomáš Hanke. The vaccines were manufactured through funds from EDCTP, IAVI and the European AIDS Vaccine Initiative 2020 (EAVI2020).
The GREAT consortium is a collaboration with the Oxford University, IAVI, Imperial College London, KAVI-Institute of Clinical Research (KAVI-ICR) at the University of Nairobi, the Uganda Virus Research Institute-IAVI HIV Vaccine Program (UVRI-IAVI), the MRC/UVRI and LSHTM Uganda Research Unit, the Kenya Medical Research Institute-Wellcome Trust Research Programme (KWTRP), and Center for Family Health Research in Zambia CFHRZ.
The killer T-cell vaccine strategy
The trial tests a candidate T-cell vaccine strategy against HIV-1. The tested regimen consists of a prime with engineered replication-deficient simian (chimpanzee) adenovirus vector ChAdOx1 followed by a heterologous boost with two replication-deficient poxviruses called MVA. These vectors deliver unique mosaic algorithm-computed immunogens derived from the six most functionally conserved (vulnerable) regions of the HIV proteome, collectively called HIVconsvX. Two regions are from the Gag including the whole capsid protein p24 and four are derived from the Pol proteins. These regions are common to most global HIV-1 variants and are hard to change and escape. These vaccines aim to induce protective killer T-cell responses targeting the most vulnerable regions on the HIV proteome. If effective, the vaccines could work across all major HIV-1 clades and be deployed in all geographical regions.