HIV Vaccine: 97% of volunteers produce antibodies in 1st trial

RIO DE JANEIRO, BRAZIL – The findings, so far, are extremely positive: the vaccine was able to boost production of the rare cells needed to generate antibodies against HIV in 97% of subjects. In phase 1 clinical trials, 48 healthy adult volunteers received either a placebo or two doses of the immunizer, along with an adjuvant developed by GlaxoSmithKline, a British pharmaceutical company.

The clinical trial was small, and the results have not yet been published in any scientific journal. Still, in phase 1, many more tests will have to be performed until the final vaccine is achieved. Even so, the news released sounds promising, both to the public and to the scientists who participated in the study.

According to IAVI data, in 2019, 38 million people in the world lived with HIV or AIDS, and 1.7 million were infected in that year alone. Of this total, 33% do not have access to the necessary treatment and consequently infect others.

How does the HIV vaccine work?

Currently, over 20 HIV vaccines are being tested. The one that is in Phase 1 clinical trials triggers B-cell activation in its first phase through a process called germline targeting. In all, the vaccine is a multi-step process to induce the production of different types of “broadly neutralizing antibodies” (better known as bnAbs).

“We and others have postulated for many years that to induce bnAbs, you must start the process by activating the right B cells,” says Dr. William Schief, a professor and immunologist at the Scripps Institute. B cells have special properties that give them the potential to develop into bnAb-secreting cells and induce them. However, only about 1 in a million of them will do this, according to Schief.

The production of bnAbs is seen as a “Holy Grail” in the scientific community. The hope is that these blood proteins will bind to HIV’s surface proteins-the so-called spicules, which allow the virus to enter human cells, just as in coronavirus-and deactivate them at the regions that are difficult to access.

“The HIV spicule protein is much more tortuous,” says Schief. As a result of the rapid mutation of the genes that form the spicule, HIV has millions of different strains. Because of this, antibodies against one strain are unlikely to neutralize the others. “And so HIV is not really one virus. It’s really 50 million different viruses around the world now.”

Source: Exame