ABSTRACT The (Phase goal of the Center for Clinical and Translational Science's (CCTS) proposed continuation II) RADx-UP 121 project is todetermine trends and disparities of SARS-CoV-2 testing, infections, and COVID-19 vaccination coverage in threetargeted Texas regions:Houston/Harris County; South Texas (Cameron and Hidalgo Counties; and 3) Northeast TX (seven counties including the city of Tyler). This effort will result in improved and expanded time related will: recent structural and access enabled multilevel, just-in- adaptive intervention trategies to reach vulnerable populations experiencing inequities to COVID-19. More specifically, in collaboration with community partners, this project 1) identify disparities and dynamics of SARS-CoV-2 testing and infections, considering data on COVID-19 vaccination; 2) identify personal, organizational, community, and factors contributing to SARS-CoV-2 testing and COVID-19 vaccination disparities, 3) expand the reach and impact of a multil evel intervention to increase motivation for and to testing and vaccination among vulnerable populations. The project's efforts will be by leveraging long-standing community partnerships. s Phase II will be informed by learnings and accomplishments from the Phase I effort, which have included: (1) Developing real-time data processing procedures and implemented quality control measures for various local data, including SARS-CoV-2 testing data, case investigation and hospital records; (2) Processing and analyzing COVID-19 case data including over 367,000 cases in Harris County, over 40,000 in Cameron County, and over 29,000 cases in Northeast Texas counties - all datasets now have common data elements and consistent formats; (3) Developing several metrics to quantify the COVID-19 disease burden for the overall population and by demographic subgroups; (4) Developing the census block group (CBG)-level disparity index, which is constructed using 12 variables from the American Community Survey (ACS) and; (5) Identifying the CBGs disproportionately affected by SARS-CoV-2 infections and prioritizing them for interventions to increase testing uptake and COVID-19 vaccination using the developed disease burden metrics and disparity index. Changes (enhancements and expansion) to be implemented in Phase II, as compared to Phase I (benchmark), include: (A) Adapting Phase I CHW-training/outreach program to include training on motivational interviewing, and an expanded focus on vaccination education and motivation/promotion of testing; (B) Enhancing 2-1-1-based education, motivation, and referral to testing and vaccination, (C) Including broader-based social media outreach, such as geo- targeted Facebook ads to motivate users to access COVID-19 testing and vaccination; (D) Conducting a panel study to compare the effectiveness of the CHW-Facilitated Self-Sampling Intervention vs. CHW Testing Navigation Intervention on participation in SARS-CoV-2 testing, and; (E) Assessing the impact and reach of multilevel COVID-19 communication networks on individuals' attitudes, intentions, and decisions on behavior surrounding SARS-CoV-2 testing and COVID-19 vaccination in underserved communities.

Narrative: This study will leverage long-standing academic-community partnerships to examine COVID-19 infection, testing, and vaccination patterns in three Texas regions (Houston/Harris County, South Texas, and Northeast Texas) to identify underserved communities. In these communities, we will provide and evaluate a multilevel intervention to increase reach, uptake, implementation, and sustainment of SARS-CoV-2 testing and COVID-19 vaccination. We will also explore the impact and reach of people's communication networks on attitudes, intentions, and decisions on behavior regarding SARS-CoV-2 testing and COVID-19 vaccination.