To put a box into the rapidly changing virus, scientists realized that they needed a combination of different HIV drugs – and that discovery led within a few years to tri-drug formulas in the mid-1990s. which turned HIV from a death penalty into an infectious, treatable disease. .
AMP’s study confirms why HIV is a “strong virus,” Corey said, but in his opinion the most important finding of the test is that it for the first time set a measurable threshold that can be shown when which monoclonal antibodies work – or when they don’t.
An experiment – developed by Dr. David Montefiore from the Duke Institute of Human Vaccination – measuring the potential of a specific antibody to prevent HIV. The AMP study found that if an antibody reached a certain level of potency against HIV sex, it would inhibit it; if it was weaker than that level, the antibody failed.
The study showed that the antibody met the threshold against 30% of the HIV strains that occurred, but was not strong enough to block other strains. Importantly, the study showed that the strength required for the antibody to work against all strains of HIV had to be about 10 times more potent than VRC01.
Corey said that is crucial for future HIV prevention drug planning.
“The test completely figured out what worked and what didn’t work,” Corey said. “Now we can use this assay to define a more powerful antibody in general. ”
During the press conference, Corey identified several new studies testing whether more potent forms of VRC01, or a combination of even more potent-neutralizing antibodies identified since 2016, to be robust to enough to prevent infection. They include studies of a longer version of VRC01, and early trials in humans of compounds of two and three different generally neutralizing antibodies.
“We can use this assay to develop broadly neutral antibodies, and it seems that with this tool we can look for new ones that are better, more powerful and cheaper,” Corey said.
With support from NIAID, the trial spanned four continents
AMP was supported by the National Institute of Allergies and Infectious Diseases and enrolled volunteers in parallel trials. The Hutch-based HIV Vaccine Testing Network, or HVTN, ran AMP tests in the U.S., South America and Switzerland. The volunteers were transgender men and people who have sex with men. The HIV Prevention Test Network, a sister group in North Carolina, ran the second part, enrolling women in seven sub-Saharan African countries.
Because VRC01 could not inhibit all sexes in an AMP study run by HVTN, the antibody was found to reduce total HIV infections by 27%. In the study in sub-Saharan Africa – which has a different family of HIV strains – it was 9%.
Dr Carl Dieffenbach, who leads the AIDS research at NIAID, said the AMP study confirmed our understanding of antibody control over HIV and made some interesting conclusions that will inform future prevention efforts.
“Initially, it showed that ingestions of this neutral antibody were safe. There were approximately 44,000 infusions in the course of this study on many continents, ”he said in an interview.
“It really gives us a hand or two. It tells us what level of nesting is required to provide protection. It also tells us how much antibody we need to stimulate with a vaccine, ”he said.