PROJECT SUMMARY/ABSTRACT Cases of COVID-19 infection in San Diego have persistently remained high in the county’s central and southern communities near the US/Mexico border, home to primarily Latino residents who have been one of the ethnic minority communities most impacted by COVID-19. To address this, our Phase I RADx-UP project partnered with San Ysidro Health (SYH), a federally qualified health center, and the Global Action Research Center (Global ARC), a social change organization, to co-create and demonstrate the impact of a PCR-based COVID-19 testing program in San Ysidro. To date, we have administered approximately 15,000 PCR tests for >10,000 community members (92% Latino) and received requests from SYH to scale-out the testing program to additional primary care clinic sites. Responsive to RFA-OD-22-006, we will continue working with our community (Global ARC) and clinical (SYH) partners to refine, specify, implement, and evaluate an implementation strategy bundle that optimizes COVID-19 testing, expanding beyond current PCR testing to focus on FDA-authorized COVID-19 rapid antigen testing. Use of self-administered rapid antigen tests will allow participants to build capacity to self-test and use health information technology to access additional clinic services. Based on initial implementation mapping with the project’s established Community and Scientific Advisory Board, three implementation strategies were prioritized to accelerate sustained uptake of rapid COVID-19 testing. These three strategies include: (1) current, walk-up onsite free testing; (2) promotores-led COVID-19 test counseling and preventive care reminders; (3) vending machines that dispense FDA-authorized self-testing kits. Our primary objectives are to: 1) refine and operationalize our multi-component implementation strategy bundle and a related set of measures of success for rapid FDA- authorized COVID-19 testing and 2) implement and evaluate impact of our innovative, multilevel, and multicomponent implementation strategy bundle to optimize COVID-19 rapid testing among underserved, Latino communities using a roll-out implementation optimization study design across four clinics over 18 months. The COVID-19 pandemic has underscored the urgent and essential need to engage invested community parties continuously and meaningfully in public health research to reduce health disparities. This proposal is well-positioned to provide a set of strategies and measures of success that can be used in settings serving underserved communities while maintaining flexibility to adjust to the changing COVID-19 landscape.

PROJECT NARRATIVE In our Phase I RADx-UP project, UC San Diego partnered with San Ysidro Health, a federally qualified health center, and the Global Action Research Center, a social change organization, to co-create and demonstrate the impact of a PCR-based COVID-19 testing program in San Ysidro, one of the most impacted areas from COVID-19 in San Diego County. To date, we have tested >10,000 community members (92% Latino) and received requests to scale-out the testing program to additional primary care clinic sites. In this Phase III proposal, we will extend work with our Phase I community and clinical partners to refine, specify, implement, and evaluate an implementation strategy bundle that optimizes COVID-19 testing, expanding beyond current PCR testing to FDA-authorized COVID-19 rapid antigen testing.