PROJECT SUMMARY This R01 application, led by an Early Stage Investigator, aims to test the effectiveness of a multilevel community- based intervention to increase uptake and adherence to oral pre-exposure prophylaxis (PrEP) among adolescent girls and young women (AGYW) in Kenya. AGYW in this setting live in a context of heightened gender inequality and risk of intimate partner violence (IPV) and represent a large subpopulation who are uniquely vulnerable to HIV infection. In addition to having higher HIV incidence, women experiencing IPV are less likely to initiate and persist with PrEP, limiting the protective benefit of this efficacious biomedical prevention intervention. Barriers to PrEP uptake and adherence occur at multiple levels of the socioecological model, including low individual self-efficacy, partner opposition, and community stigma. Tu'Washindi na PrEP (We are Winners with PrEP) is a multi-level, community-based intervention designed specifically to address these challenges among AGYW in Siaya County, Kenya. Designed by our team using participatory methods engaging local AGYW (R34 MH114519), the intervention includes three components delivered over 6 months: an eight-session, empowerment-based support club for AGYW, community sensitization targeted toward male partners, and PrEP education events for couples. Activities are designed to be integrated into youth-focused programming to ensure efficiency and sustainability. Results from a pilot cluster- randomized controlled trial conducted with 100 AGYW at six sites indicate high feasibility and acceptability, and preliminary effectiveness: intervention arm participants had 2-fold higher PrEP uptake and adherence (p<0.05), with less frequent or severe IPV than control arm participants. The proposed study builds on these promising results and aims to evaluate the intervention in a fully powered cluster-randomized controlled trial across 22 administrative wards in Siaya County, Kenya, enrolling 72 AGYW per ward (total N=1,584). The primary objectives (Aim 1) will be to test the effectiveness of the intervention on PrEP uptake and adherence immediately post-delivery (month 6 post- enrollment) and 6 months later (month 12). As secondary objectives we will test the intervention effect on IPV and relationship power (Aim 2). A rigorous process evaluation will explore mechanisms of change, contextual factors, and implementation considerations to inform future refinement and scale-up, using programmatic data, participant questionnaires, and qualitative interviews with participants and providers (Aim 3). The proposed study builds directly on our R34 intervention development work to develop the evidence base for this youth-designed, multi-level HIV prevention intervention. If effective, Tu'Washindi will be ideally positioned for sustainable integration into existing youth-focused programming to expand and support PrEP use in this priority population.