We have entered a new era in HIV prevention whereby priorities have expanded from biomedical discovery to include implementation, eff ectiveness, and the eff ect of combination prevention at the population level. However, gaps in knowledge and implementation challenges remain. In this Review we analyse trends in the rapidly changing landscape of HIV prevention, and chart a new path for HIV prevention research that focuses on the implementation of eff ective and effi cient combination prevention strategies to turn the tide on the HIV pandemic. HIV pandemic.