The International AIDS Vaccine Initiative (IAVI) and Scripps Research recently announced the results of a major phase I clinical trial. Researchers tested a new vaccine approach designed to prevent HIV infections by stimulating the production of immune cells. rare. These cells are necessary to create the proper antibodies to fight HIV.
The trial saw 48 participants divided into a low dose group or a high dose group. They received the candidate vaccine or a placebo in two doses two months apart. Of those who received the vaccine, 97 percent had developed the proper immune cells to respond to an HIV infection.
“This study demonstrates a proof of principle for a new HIV vaccine concept, a concept that could also be applied to other pathogens,” said Dr. William Schief, professor and immunologist at Scripps Research and executive director of vaccine design at the IAVI Neutralizing Antibody. Center (NAC), whose laboratory developed the vaccine, said in a statement. “With our many collaborators on the study team, we demonstrated that vaccines can be designed to stimulate rare immune cells with specific properties, and this targeted stimulation can be very efficient in humans. We believe this approach will be key to making a vaccine against HIV and possibly important to making vaccines against other pathogens. “
The results were presented at the International AIDS Society HIV Research for Prevention (HIVR4P) virtual conference in February. The team has been looking to stimulate the body to create broadly neutralizing antibodies, or bnAB, specialized blood proteins that can stick to spikes on the surface of HIV. This is an immune response that can neutralize various strains of the virus.
“We and others posited many years ago that to induce bnAb, you must start the process by activating the correct B cells, cells that have special properties that give them the potential to become bnAb-secreting cells,” explained Schief. “In this assay, the target cells were only one in a million of all naive B cells. To get the correct antibody response, we must first prime the correct B cells. The data from this trial affirm the ability of the vaccine immunogen to do this. “
This preparation approach would be the first step in a series that would allow an individual to have developed immunity against the disease. And the team believes that the preparation can be used as a starting point in vaccines that fight different strains of influenza, as well as dengue, Zika, hepatitis C viruses and even malaria.
The clinical trial, known as IAVI G001, is a fantastic result. Researchers are partnering with the biotech company Moderna (from the famous COVID-19 vaccine) to develop and test an mRNA-based vaccine that elicits this immune response.