The advent in 1996 of potent combination antiretroviral therapy (ART), sometimes called HAART (highly active antiretroviral therapy) or cART (effective combination antiretroviral therapy), changed the course of the HIV epidemic [1]. These “cocktails” of three or more antiretroviral drugs used in combination gave patients and scientists new hope for fighting the epidemic [2], and have significantly improved life expectancy—to decades rather than months [1,3].
For many years, scientists believed that treating HIV-infected persons also significantly reduced their risk of transmitting the infection to sexual and drug-using partners who did not have the virus. The circumstantial evidence was substantial, but no one had conducted a randomized clinical trial— the gold standard for proving an intervention works.