Eastern and Southern Africa is the region with the biggest epidemic but the most successful HIV response to date by many measures. More than 1.3 million new HIV infections in children under five have been prevented since 2010, and more than 90 per cent of pregnant women living with HIV receive antiretrovirals. However, progress has been less substantial in other aspects of the response. Annual reductions in new HIV infections among adolescents (aged 10–19), especially girls, have not been fast enough to curb the epidemic. Critical needs include improving HIV testing, treatment and viral suppression among adolescents; reaching mothers yet unreached with services for the prevention of mother-to-child transmission; and retaining them in care and treatment throughout pregnancy and the breastfeeding period.