A novel experimental HIV vaccine developed by Scripps Research and IAVI showed promising immune system responses during its first-ever in-human clinical trial.
The vaccine against HIV readied the immune system during the first stage in the production of broadly neutralizing antibodies. Approximately 38 million people around the world live with HIV. It is one of the toughest viruses to target with a vaccine, so this is very positive news.
The Scripps Research and IAVI team's vaccine was able to stimulate the production of rare immune cells, which then begin the process of creating antibodies to fight the virus — a response that was generated in 97 percent of the clinical trial's participants.
The researchers note that this is not only good news for continuing in the search for a vaccine against HIV but also against other fast-mutating viruses.
What the team discovered during its search for an HIV vaccine
It's been years since researchers began working towards stimulating the immune system to produce powerful antibodies that are capable of neutralizing various strains of HIV. These are called "broadly neutralizing antibodies," or bnAbs. BnAbs attach themselves to HIV spikes, and disable them in areas that are hard to reach, this part of the virus also doesn't vary hugely between strains.
"We and others postulated many years ago that in order to induce bnAbs, you must start the process by triggering the right B cells — cells that have special properties giving them the potential to develop into bnAb-secreting cells," explained William Schief, a professor and immunologist at Scripps Research and executive director of vaccine design at IAVI's Neutralizing Antibody Center, whose laboratory developed the vaccine.
"To get the right antibody response, we first need to prime the right B cells. The data from this trial affirms the ability of the vaccine immunogen to do this."
The team carried out two clinical trials with a total of 48 healthy adult volunteers. Participants either received a placebo, or two doses of the vaccine compound eOD-GT8 60mer, as well as an adjuvant developed by the pharmaceutical company GSK.
This priming step is the first one in a multi-step vaccine process that works towards eliciting different types of bnAbs, with the ultimate goal of stopping the virus entirely.
The findings were shared virtually at the International AIDS Society HIV Research for Prevention conference on February 3. This research paves the way for further clinical trials that can refine and extend this method, ultimately leading to a vaccine against HIV.