220.7 PROJECT SUMMARY/ABSTRACT Stigma is a main driver of HIV disparities among Latino men who have sex with men (LMSM), negatively affecting non-injection substance use (e.g. methamphetamine) and PrEP uptake. Addressing factors that influence PrEP cascade progression, such as intersectional stigma and methamphetamine use, are essential to ending the HIV epidemic. Intersectional stigma is a complex social phenomenon experienced across various stigma sources (i.e. family, friends, others), mechanisms (i.e. anticipated, enacted), and types (i.e. race/ethnicity, sexuality, masculinity), which intersect to produce and exacerbate deleterious health outcomes among LMSM. Social network analysis techniques can be leveraged to examine how LMSM interact with and are affected by network members and inform targets for meaningful interventions focused on which network members (1) stigmatize LMSM and (2) provide social support to buffer against the effects of intersectional stigma on methamphetamine use risk and PrEP cascade progression. This K01 will provide the candidate, Dr. Algarin, with skills to conduct complex longitudinal multi-level structural equation modeling to examine the direct and indirect effects between intersectional stigma and methamphetamine use risk and PrEP cascade progression through coping, resistance, and resilience (AIM 1) and how sources of social network intersectional stigma moderate these pathways (AIM 2) leveraging data from 500 LMSM enrolled in NEXUS: a novel social network approach to study the effects of intersectional stigma on HIV prevention among Latino MSM (NEXUS; R01MH123282; PI: Smith). Using a community-engaged approach, Dr. Algarin will draw from these analyses to adapt a multi-level intervention to address intersectional stigma through coping, resistance, and resilience to decrease methamphetamine use risk and improve PrEP cascade progression (AIM 3). As an emerging gay Latino scholar, Dr. Algarin will leverage the UCSD training infrastructure to build his professional independence and skills to promote HIV prevention interventions in medically marginalized groups, positioning him as the next generation of under-represented minority scholars to end the HIV epidemic among MSM of color disproportionately burdened by HIV in the US. Specifically, Dr. Algarin seeks training to advance his statistical capacities (T1), gain proficiency multi-level intervention theories and concepts (T2) and multi-level intervention development and adaptation (T3), gain additional training in the ethical conduct of research (T4), and build skills for his professional development (T5). This K01 will provide Dr. Algarin with the necessary training and data to forge his research independence and produce a competitive future R34 to test the community- engaged, multi-level intervention he adapts as part of this study.

220.8 PROJECT NARRATIVE Latino men who have sex with men (LMSM) face one of the largest disparities in new HIV diagnoses nationally, likely because they face intersectional stigma towards their ethnic, sexual, and gender identities (i.e. adherence to masculinity norms) which negatively affects both methamphetamine use and PrEP cascade progression. Social network analysis employing longitudinal multilevel structural equation modeling is an innovative method for studying how intersectional stigma is experienced by members of LMSM’s social network and can differentiate between which network members and under what social contexts stigma reduction interventions could decrease methamphetamine use risk and improve PrEP cascade progression to reduce HIV incidence. Through this K01, Dr. Algarin will leverage the UCSD training infrastructure to build his professional independence and skills for promoting HIV prevention in medically marginalized groups, positioning him as a leader among the next generation of under-represented minority scholars to end the HIV epidemic among MSM of color disproportionately burdened by HIV in the US.