Study Title: A phase 1/2a open label trial to assess safety and immunogenicity of candidate T-cell vaccines ChAdOx1.HTI and MVA.HTI given sequentially to healthy HIV-1/2 negative adult volunteers in Oxford, UK
Chief Investigator: Dr Paola Cicconi
Sponsor: University of Oxford
Funder: Horizon 2020
An estimated 36.7 million people globally are chronically infected with HIV. Control of the HIV epidemic remains one of the top global health priorities. Remarkable gains have been achieved in decreasing HIV transmission and AIDS-related deaths due to global scale-up of antiretroviral therapies and efforts to strengthen HIV prevention and treatment programmes1. Nevertheless, the pace of decline in new HIV infections is far too slow to reach the Fast-Track Target agreed upon by the United Nations General Assembly in 2016: fewer than 500,000 new infections per year by 2020. A high proportion of people living with HIV are still unaware of their status, which limits the use of effective treatments; the global treatment coverage was only 56% of the estimated number of people living with HIV by mid-20172. One of the main reasons why people are reluctant to get tested, disclose their HIV status and receive treatment is the fear of stigma and discrimination. HIV infection will likely remain a global epidemic in the foreseeable future especially in the developing world where the medical infrastructure struggles more to address fears and support treatment. There is good evidence that undetectable HIV viral load might be a threshold below which sexual HIV transmission does not occur, however antiretroviral drugs’ effective administration requires rigorous daily compliance3, there are toxicities associated with their long-term use4-6, and the circulating viruses can develop resistance to treatment. For these reasons, the development of effective and accessible vaccines which may be used both prophylactically and therapeutically represent the best long-term hope for bringing the global HIV/AIDS epidemic under control. For the most efficient control of HIV, a vaccine will likely have to induce both broadly neutralising antibodies and effective CD8+ T-cells7. The approach taken in the design of the vaccine for the proposed trial has been to focus on the induction of protective T-cell responses, which will likely be key in controlling and eradicating HIV following initial transmission.