[Editor's note: The recent HPTN 052 study that showed such dramatic success from antiretroviral therapy (ART) being given early to help prevent HIV transmission among HIV discordant couples followed on the footsteps of early research that suggested such a trend. One such study was conducted in Uganda between 2003 and 2007. It followed ART-naïve, HIV-infected adults in an AIDS program that provided many standard prevention interventions, including annual counseling and testing for cohabiting partners, risk reduction plans, condom distribution, and prevention support. The HIV-infected partners were started on ART. The study found that despite a reported increase in sexual activity that was 41% at 36 months, consistent condom use was high with discordant partners, and estimated HIV transmission risk was reduced 91%. AIDS Alert asked two investigators with the Ugandan study to discuss their research findings, particularly in light of the recent announcement that HPTN 052 was halted early so all study participants could be offered early ART. Rebecca Bunnell, ScD, MED, associate director for public health practice at the National Center for Chronic Disease Prevention and Health Promotion of the Centers for Disease Control and Prevention (CDC) in Atlanta, GA, and Jonathan Mermin, MD, MPH, director of the division of HIV/AIDS prevention at the CDC, answered a few questions about their study and its implications in this email question-and-answer (Q&A) exchange.]