Seeking to shrink the viral reservoir, researchers compared an investigational agent known as ABX464 with a placebo among 30 people who had fully suppressed HIV thanks to antiretroviral (ARV) treatment. ABX464 works by preventing HIV-infected cells from producing viable new copies of virus. Instead, the cells produce small elements called peptides that draw the immune system’s attention to an infected cell, prompting a cell-eliminating response. After 28 days, participants stopped all treatment, including ARVs. Four weeks later, eight of those who received ABX464 were considered to have responded to the treatment, with the amount of HIV DNA in their bodies—an approximate measurement of the reservoir—dropping by more than 25 percent, for an average drop of 38 percent among them. However, ABX464 was not linked to a reduction in the time to the viral load’s rebound after the ARV treatment interruption.