ZAIMARA: Zambian Informed Motivated Aware and Responsible Adolescents and Adults - Project Abstract Zambia is struggling to meet the 95-95-95 targets for adolescent girls and young women (AGYW). HIV prevalence in 15-19 year-olds is 3.3%, and AGYW are 4 times more likely to acquire HIV than their male peers (8.6% vs. 2.1%). HIV incidence increased in AGYW from 2010-2020 while decreasing in all other groups, yet HIV testing rates are low (45.4%), and 71.2% do not know their HIV status. The proposed hybrid trial will evaluate the effectiveness and implementation of a CDC “best-evidence” intervention, Informed Motivated Aware and Responsible Adolescents and Adults (IMARA), recently adapted for South Africa (IMARA-SA) with promising effects on AGYW STI incidence, sexual risk taking, PrEP uptake, and mental health. Guided by the Exploration, Preparation, Implementation, Sustainment framework and an Implementation Research Logic Model, this study addresses a key driver of poor sustainability of evidence-based programs in low-resource settings - attrition in health workforce due to mental distress and low job satisfaction – by evaluating the impact of mental health screening and referral on peer leaders delivering IMARA. Building on preliminary focus groups with key stakeholders in Zambia, the study aims to: (1) Tailor IMARA-SA for the Zambian context to produce ZAIMARA; (2) Compare the effects of ZAIMARA vs. a general health promotion program on AGYW HIV testing uptake at 6 months (primary clinical outcome), incident STIs (including HIV), sexual behavior, and PrEP uptake (secondary clinical outcomes) at baseline, 6-, 12-, 18-, and 24 months. (3) Examine the impact of mental health screening and referral vs. a general check-in on peer leader job retention. (4) Evaluate ZAIMARA implementation outcomes using mixed methods and key informant interviews. The partnership between the Centre for Infectious Disease Research in Zambia (CIDRZ) and the Center for Dissemination and Implementation Science (CDIS) in the United States will ensure the expertise needed to complete the study in five geographically distinct communities in Lusaka Province, the region with the highest HIV prevalence in Zambia, while building capacity for implementation science research. This is a theoretically-grounded, hypothesis-driven hybrid-trial that addresses critical gaps in the HIV prevention continuum for Zambian AGYW, with a long-term goal to sustain effective programs that reduce HIV/STI infections.