Project Summary/Abstract The COVID-19 pandemic significantly affects the entire State of Arizona but impacts communities along the border with Mexico disproportionally. Majority Latinx and American Indian communities along this border have higher infection rates and less access to testing and vaccination. This proposed supplement aims to increase access to testing and related services for these underserved transnational communities. The expansion of our current community-driven and culturally congruent project will advance knowledge about barriers to care and effective strategies to increase testing and vaccination in the border region. This application extends the work of ASU’s health disparities U54 center grant (RFA-MD-17-005; 5U54MD002316) and its RADx-UP supplement (3U54MD002316-14S1) by reducing disparities in COVID-19 diagnostics, vaccination, education, wraparound services and health care, with the goal of improving the health of vulnerable and underserved communities. The aims of this emergency competitive revision closely match and enhance the aims of the current U54 award and its RADx-UP supplement. The focus on populations along the AZ-Mexico border will add to existing knowledge about assets and vulnerabilities of diverse transnational communities disproportionally affected by the pandemic. The approach empowers local communities, is data driven, and creates the infrastructure capacity for community-driven delivery of care. Following a Community Based Participatory Research (CBPR) orientation, the revised supplement expands our existing R.A.P.I.D. program by improving access and decreasing hesitancy to COVID-19 testing and vaccination among underserved and vulnerable populations in the border region. Equality Health Foundation (EHF) will continue to serve as the lead community partner for the proposed revised supplement and the ASU Biodesign Clinical Testing Laboratory (ABCTL) will provide and analyze the saliva-based polymerase chain reaction (PCR) testing for SARS-CoV-2. Local partners coordinated by EHF under the One Community Initiative against COVID-19 will implement the vaccination program. Over two years, the revised supplement aims to reach 7,000 additional community members living and working along the AZ-Mexico border. CDCC surveys from border communities will be added to the ongoing longitudinal study we are conducting to assess the intervention’s impact and also by comparing randomly selected participants (N=200) with a matched comparison group (N=200) randomly selected from regular testing sites. We will also conduct ongoing COVID-19 variants sequence validation among those tested and inform appropriate health authorities if significant variants emerge. The transdisciplinary team has the infrastructure, capacity, and community partnerships in place to implement the project effectively and efficiently. ASU’s existing NIMHD-funded U54 center, guided by its Community and Scientific Advisory Board...