NIAID Now | March 18, 2021
Although the spread of HIV has slowed down thanks to risk-reduction measures, prevention efforts, and oral antiretroviral preexposure prophylaxis (PrEP), there are more than 1.5 million new cases of the human immunodeficiency virus (HIV) each year worldwide. The Antibody Mediated Prevention trials included two clinical trial cohorts, to test the ability of the monoclonal antibody VRC01 to prevent HIV acquisition. The study enrolled participants from three different continents, including at-risk cisgender men and transgender people and at-risk women in sub-Saharan Africa. Participants were healthy, HIV-uninfected adults 18-40 years old randomly assigned to receive either the VRCO1 antibody or a placebo 8 weeks at a time for a total of 10 infusions over the course of 20 months.
Researchers found that, although the VRC01 antibody did not prevent overall HIV-1 transmission, VRC01 treatment was linked to lower risk of acquisition of HIV-1 isolates that had in vitro sensitivity to the antibody. For women in sub-Saharan Africa who were at risk for HIV-1 infection and were exposed to subtype C variants, VRC-01 demonstrated 75% protection against this group of viruses. This was also the case at other sites, including at-risk persons in South America, Switzerland, and the United States who were assigned male sex at birth or were transgender, and who were exposed to subtype B variants. These findings support that pre-exposure prophylaxis using broadly neutralizing antibodies can be a promising strategy to prevent HIV spread.
Reference: Corey L et al. Two Randomized Trials of Neutralizing Antibodies to Prevent HIV-1 Acquisition. N Engl J Med. 2021 Mar 18;384(11):1003-1014.