Dulce Ferraz is a social psychologist with a PhD in public health, currently working at the Oswaldo Cruz Foundation (Fiocruz) in Brazil. Her research focuses on the intersections between health, gender, sexuality and human rights, and she is particularly interested in understanding the psychosocial dimensions involved in HIV prevention. Over the past 10 years, she has been working on PrEP demonstration studies, namely PrEP1519, Combina and ANRS-PISTAS. Developed in collaboration with Brazilian (USP, UFBA) and French (Université Lyon 2) universities, these studies focus on key populations, such as trans women, men who have sex with men, adolescents and sex workers. They apply community-based research methods, aiming to improve PrEP access and retention among these groups.