PROJECT SUMMARY/ABSTRACT Pregnant adolescents face synergistic challenges in the context of HIV – heightened risk of maternal infection, vertical transmission, and maternal and fetal morbidity and mortality compared to adult women living with HIV – and a largely absent evidence base to inform prevention and treatment strategies. Despite increasing global attention on HIV among adolescent girls and young women, and strong consensus around the urgent need to attend to pregnant women in the HIV research agenda, persisting complexities at the intersection of pregnancy and adolescence have amplified reticence around their inclusion in research. This project seeks to address these questions and confusions around the ethical permissibility of including pregnant adolescents in research. To this end, we will build on the substantial contributions our team has made through the R01 NIAID funded PHASES Project (Pregnancy and HIV/AIDS: Seeking Equitable Study), which developed an Ethics Guidance to advance the responsible inclusion of adult pregnant women in research to prevent and treat HIV/co- infections. Building on PHASES findings and core consensus principles in PHASES Ethics Guidance, our goal is to provide empirically informed guidance for conducting ethically responsible HIV/co-infections research with pregnant adolescents. To achieve this goal, PHASES Adolescence aims: 1) To identify scientific priorities in, perceived barriers and enablers to conducting HIV/co-infections prevention and treatment research with pregnant adolescents through interviews and engagement with stakeholders in the HIV research and advocacy communities in the US and Southern Africa, including investigators, community advisory board members, and HIV youth advocates and; and to characterize reasoning around participation in such studies from the viewpoints of affected adolescents through interviews with pregnant adolescents with or at risk for HIV in the US and Southern Africa; 2) To identify conditions for responsible HIV/co-infections research with pregnant adolescents that are responsive to the above priorities, barriers, enablers and viewpoints, through scholarly ethical and regulatory analysis, and interviews and engagement with stakeholders involved in the ethical and regulatory review and oversight of research, including ethicists, regulatory and policy experts, and research ethics committee members; and 3) To develop an adolescence-specific framework for advancing HIV research in pregnancy, whose utility and acceptability will be vetted by stakeholders in the HIV research and advocacy communities, and those involved in the ethical and regulatory oversight of research, delineating when and under what circumstances pregnant adolescents can and should be included in HIV/co-infections research. Through a rigorous methodological design and the individual and collaborative experience of project investigators in empirical research, moral analysis, and ethics guidance developmen...