There are an estimated 5000 new HIV transmissions every day. Around 70 per cent of the 37 million people living with HIV globally are in sub-Saharan Africa.
Of the 1.8 million new HIV transmissions worldwide in 2017, 800 000 occurred in eastern and southern Africa. New, effective prevention strategies are essential to reducing HIV transmission.
So what will it take to reduce HIV transmission? Prevention.
This is why researchers around the world are working hard to find a vaccine that is safe and effective. This requires extensive testing, starting in laboratories and then moving to animal trials. Then comes the crucial human clinical trials. A number of these are underway at the moment, running at different sites in 12 countries across four continents.
These trials are being conducted under the auspices of the HIV Vaccine Trials Network. The network currently runs 49 clinical trial sites in nine countries with 18 ongoing trials, four of which are efficacy trials. Three trials are of particular interest as they have already been running since 2016 and are expected to close in late 2021.
The first is known as the Antibody Mediated Prevention studies. It’s testing whether a broadly neutralising antibody can prevent HIV acquisition in people. The second, called Uhambo, is testing an experimental vaccine regimen against HIV. And the third, Imbokodo, is testing an experimental vaccine regimen that’s designed to offer protection against a variety of global HIV strains.
These studies involve thousands of people all over the world, including countries hardest hit by HIV. If any of them are successful – that is, if the drugs being tested prove to be safe and effective for human use – the 30-year fight to end the HIV/AIDS epidemic will take a huge step towards victory.
It has been incredibly hard to make a vaccine against HIV. Some of the hurdles to overcome include the genetic diversity of HIV, which is greater than any other pathogen, the lack of a good animal model, no natural human cure and the complexity of the virus’s outer structure or envelope.
Study volunteers randomly receive either a higher dose of the antibody, a lower dose, or a placebo. Neither the volunteers, nor the investigators, know who receives which type of infusion during the study. The volunteers receive a total of 10 infusions, once every 8 weeks, and they are then followed for an additional 20 weeks.
They also receive standard prevention interventions including oral pre-exposure prophylaxis (PrEP). The trials will examine the safety, tolerability and effectiveness of the antibody infusion. Trial results are expected in 2022.
Many scientists believe that a vaccine developed using broadly neutralizing antibodies could protect healthy people from HIV infection. The AMP Studies are contributing to the assessment of this hypothesis. Additionally, the studies aim to clarify what level of broadly neutralising antibodies a vaccine, or other long-acting HIV prevention method, needs to achieve and maintain for long-term protection from HIV.
If any of the vaccines or antibodies are effective, it will unleash an enormous explosion in scientific enquiry to improve, adapt and, most importantly, bring a new form of HIV prevention to people.
https://www.the-star.co.ke/health/2019-06-16-kenyans-participate-in-hiv-vaccine-trial/