This joint stocktaking report highlights the importance of knowing the features of different AIDS epidemics in order to contain or reverse them. It argues for expanded paediatric AIDS testing and treatment as well as prevention of mother-to-child transmission and new infections among adolescents and young people. It also advocates for expanded protection and care for the approximately 15 million children globally who have lost either one or both of their parents due to AIDS, sparking greater attention to the needs of all vulnerable young.