Project Summary/Abstract Kenya is one of few countries burdened by a combination of high rates of mother-to-child transmission (MTCT) of HIV, large numbers of adolescents living with HIV (ALHIV), and elevated adolescent fertility rates. Pregnant ALHIV are less likely than adults to attend antenatal care clinics and to receive prevention of MTCT (PMTCT) services, thereby contributing to the high MTCT rate. Previous work among 15-19-year-old Kenyan ALHIV, including some who were pregnant, found that stigma, undisclosed HIV status, and lack of social support may be key barriers to engagement in PMTCT services. Thus, addressing barriers to disclosure and social support may mitigate harmful effects of the intersecting stigmas of HIV and pregnancy on health outcomes. Although mixed, study findings suggest that mHealth interventions that use text messaging (SMS) may improve PMTCT outcomes. They are, however, limited in their ability to facilitate behavior change via support mechanisms or skill development. Growing evidence highlights the promise of digital interventions as important tools for improving HIV outcomes and communication with parents. However, digital interventions to address the effects of stigma have not been explored among pregnant ALHIV. This study will build on previous work and draw on an integrated conceptual framework to develop and evaluate a digital intervention for pregnant unmarried ALHIV. The intervention will include SMS for reminder purposes and web-based virtual simulations, gamified elements, and didactic content to educate and build relevant stigma-related skills. Acceptable approaches will be identified to involve family caregivers in addressing the detrimental effects of the intersecting stigmas on pregnant ALHIV. Family caregivers are an important yet underappreciated and understudied source of social support for pregnant unmarried ALHIV. Together, these are expected to improve engagement in PMTCT services among pregnant ALHIV. The study specific aims are to: (1) Develop and evaluate a digital intervention for pregnant unmarried ALHIV aged 15-19 to increase awareness of stigma and its consequences; improve disclosure self-efficacy and skills; and facilitate enlistment of family caregivers as social support allies to enhance uptake of PMTCT services; and (2) Identify acceptable approaches to increase awareness about stigma and enhance skills in communication and provision of social support among family caregivers. We will use data from individual interviews with pregnant ALHIV and joint interviews with pregnant ALHIV/caregiver dyads to develop initial intervention specifications and mock-ups. We will then conduct focus group to obtain feedback on sample materials in order to refine the materials and develop an intervention prototype. We will then conduct a pilot to evaluate acceptability, usability, and preliminary efficacy of the prototype. We will conduct focus groups with caregivers to identify acceptable approaches to...