The Prevention Sciences Program (PSP) aims to develop tools to reduce HIV incidence in at-risk populations through innovative research on microbicides, pre-exposure prophylaxis, and treatment strategies. Future directions include enhancing prevention strategies for vulnerable groups, improving linkages to care, and integrating behavioral research with clinical and preclinical efforts. Collaborative networks such as IMPAACT and HPTN focus on recognizing high-risk populations and advancing the effectiveness of HIV prevention interventions.