 The PREP-1519 study was developed in Brazil in 2017 to provide evidence for the use of pre-exposure prophylaxis, PREP, among adolescents. It was made possible by the collaboration of various stakeholders including governmental bodies, scientists and activists. These collaborations enabled the study to be completed despite conservative political climates in Brazil. This article was authored by Sandra Garrido de Barros, Sandra Assis Brazil and Thais Regis Aranya Rossi.