Setting the scene, setting the targets. The Joint United Nations Programme on HIV/AIDS prevention targets of 2016 and estimating global pre-exposure prophylaxis targets.

Commitment to ambitious and time-bound targets for HIV interventions has been part of the response from the beginning of the HIV epidemic. The Joint United Nations Programme on HIV/AIDS (UNAIDS) HIV primary prevention workA is built on five pillars that include offering pre-exposure prophylaxis (PrEP) to population groups at substantial risk of HIV infection. After a slow start, countries are now setting coverage targets for PrEP, but the weakness of epidemiological, demographic and behavioural data at subnational level in many countries where there is a high burden of new HIV infections, makes it difficult to define the locations and populations where to offer PrEP. This article reviews the history and challenges of PrEP target setting and suggests some possible ways of strengthening the process. Reviewing program data will identify gaps in reaching key and other priority populations for whom coverage targets were set and help to refine the offer of PrEP.