Giving infusions of the antibody VRC01 to people with HIV does not significantly delay the rebound of their virus after they stop taking standard antiretroviral (ARV) treatment.

Researchers conducted two studies of 23 people with HIV who received VRC01 infusions, publishing their findings in The New England Journal of Medicine.

Participants in both studies, who were all taking ARVs, received regular intravenous infusions of VRC01. After they stopped taking ARV treatment, the participants in each study saw their virus rebound a median 39 days and 28 days later, respectively. This represented only an apparent slight delay from the typical two weeks that HIV takes to rebound after people stop their ARVs.

The treatment was well tolerated.

Looking at the HIV isolated from the study participants before and after their viral rebound, the researchers found that the virus was not as susceptible to VRC01. Such viral resistance to the antibody suggests that researchers will need to investigate using such antibodies in combination, just as with standard combination ARV regimens.

Scientists are conducting a separate ongoing study of VRC01 as pre-exposure prophylaxis (PrEP) against the virus among HIV-negative individuals.

To read a press release about the studies, click here.

To read an abstract for the studies, click here.