Implementation Science to Understand and Design Stakeholder Informed Innovative Interventions to Improve Adolescent and Youth HIV Prevention and Care Continuums in Rural and Urban Uganda - PROJECT SUMMARY: Adolescents and young adults (AYA) have a high HIV incidence and poor outcomes along the entire HIV prevention and care cascades compared to adults. Despite the high HIV burden, both uptake of oral PrEP (HIV negatives) and achieving viral suppression (HIV positives) are sub-optimal among youth in Sub-Saharan Africa. Among youth in Uganda, uptake and persistence on oral PrEP is low, with reasons for discontinuation including: pill burden, low perceived severity of HIV, need for partner or parental approval, HIV- related stigma, fear of side-effects and health facility barriers. Cabotegravir, a is new long-acting antiretroviral (CAB-LA) and highly efficacious PrEP choice that can mitigate barriers to use of daily oral PrEP. We propose to evaluate evidence-based HIV prevention and care interventions to improve implementation outcomes among high-risk AYA (15-24 years) in Uganda. The study covers the continuum of care, will use novel screening methods for HIV risk, will involve teams that are highly experienced in youth-focused clinical trials and implementation science (ImS), will implement MOH approved community differentiated service delivery models for delivery CAB-LA, will evaluate the implementation of the SEARCH-Youth (SY), a multi-component intervention comprising of life-stage based assessment and support to increase viral suppression in high-risk AYA with HIV, and will use hybrid effectiveness implementation designs to assess these evidence-based interventions. Our aims include: Aim 1: Using the consolidated framework for implementation research (CFIR), we will identify determinants of potential implementation success of two innovations: CAB-LA and SY implementation at the community, clinic, provider, and patient levels in 5 geographically distinct sites in Uganda. Aim 2a: Using a hybrid effectiveness implementation type II design, we will assess the uptake and persistence of CAB-LA. We will conduct a randomized prospective study to assess effectiveness for the provision of CAB- LA among high risk AYA. Effectiveness outcome will be proportion of study subjects who have initiated CAB-LA and persisted at 18 months of follow-up comparing facility and community delivery options. Implementation outcomes will be feasibility, acceptability, adoption and maintenance using RE-AIM. Aim 2b: Using a hybrid effectiveness implementation type III design we will assess implementation (feasibility, adoption, fidelity, and sustainment) and effectiveness of the SY intervention in increasing long-term virologic suppression (<200 c/mL) at 18 months of follow-up in 5 CRPS using RE-AIM. Aim 3: We will use platforms in aims 1 and 2 to strengthen capacity of ImS and to translate findings into policy and guidelines. Our study involves solid community and institutional partnerships and builds on a strong multi-disciplinary team highly experienced in innovative methods and implementation science in sub-Saharan Africa. The project, building on PATC3H and AHISA, is responsive to WHO’s, Uganda’s MoH priorities regarding the gap in HIV services for highly vulnerable AYA. It will test a novel, scalable and integrated approach to initiate and sustain support for high-risk AYA in LMIC.