PROJECT SUMMARY/ABSTRACT Despite remarkable progress in HIV testing and treatment, HIV incidence remains unacceptably high among women and girls in eastern and southern Africa. In Uganda, HIV infections are concentrated among women at elevated HIV risk due to factors such as working in venues where transactional sex is common. Although oral pre-exposure prophylaxis (PrEP) is being scaled up, many women at elevated HIV risk face barriers to accessing oral PrEP at health facilities and to storing and adhering to pills. A new era of choice in biomedical HIV prevention, including the dapivirine vaginal ring (DVR) and long-acting cabotegravir (CAB-LA), presents an opportunity to reduce new infections. Post-exposure prophylaxis (PEP) could fill gaps in coverage. As new choices in HIV prevention are rolled out, strategies are needed to empower women to choose among prevention products and support sustained use. Our study team developed and tested the SEARCH Dynamic Choice HIV Prevention (DCP) intervention (including product choice: PrEP or PEP, with option to switch over time, choice of facility or community-based visits, and provider training on patient-centered care). In three randomized trials in outpatient, antenatal, and community settings, DCP increased time covered by a biomedical prevention product over two-fold compared to standard of care prevention services. However, there were gaps in engaging women who work in venues in the DCP model. We have conducted formative work, in collaboration with our Community Advisory Board, to tailor the effective DCP intervention to further reach and engage women at elevated HIV risk. Key recommendations from this work included increasing access to long- acting product choices, expanding outreach beyond facilities, and extending existing peer services for HIV prevention. Peer approaches are recommended in national guidelines and are being successfully implemented to reach women at elevated risk for HIV testing and prevention services – but peer models have not yet been deployed to deliver biomedical prevention choices. In this application, we propose to optimize and test a Peer- led Dynamic Choice HIV Prevention intervention to catalyze choice and use of biomedical prevention products. We will test the hypothesis that Peer-led Dynamic Choice HIV Prevention (with choice of oral PrEP, DVR, CAB-LA, plus low-barrier PEP access) will increase biomedical prevention coverage compared to standard of care among women at elevated HIV risk in southwestern Uganda. The proposed aims are: 1) To refine and optimize the Peer-led Dynamic Choice HIV Prevention intervention; 2) To determine the effect of the Peer-led Dynamic Choice HIV Prevention intervention on biomedical prevention coverage in a Hybrid Type 1 effectiveness-implementation cluster randomized trial; 3) To assess costs, efficiency, and cost-effectiveness of Peer-led Dynamic Choice HIV Prevention. Collectively, these aims will provide evidence for peer-led models to...