Identifying and addressing critical social, ethical, and behavioral factors associated with COVID-19 testing and vaccination among Spanish speakers - Summary Latinx communities are disproportionately affected by the COVID-19 pandemic, with Spanish-speaking Latinx communities carrying even heavier burdens of infection, hospitalization, and mortality. Major barriers to COVID-19 testing and vaccination exist, and a profound need remains to understand and address the social, ethical, and behavioral implications (SEBI) of COVID-19 testing and vaccination within Latinx communities. Our well-established community-academic partnership proposes a rigorous mixed-methods, community-based participatory research (CBPR) study better understand the SEBI of COVID-19 testing and vaccination and to refine and test a novel and culturally congruent intervention to increase COVID-19 testing and vaccination within Spanish-speaking Latinx communities. In Aim 1, we will conduct individual in-depth interviews with health providers and representatives from Latinx- serving community-based organizations and focus groups with Spanish-speaking Latinx community members to expand our understanding of the individual, interpersonal, institutional, community, and policy factors influencing COVID-19 testing and vaccination within Spanish-speaking Latinx communities. In Aim 2, we will integrate findings from other relevant COVID-19 studies and from Aim 1 to refine a Spanish-language intervention known as NuestraSaludSegura (Our Safe Health) designed to increase COVID-19 testing and vaccination among Spanish-speaking Latinx persons. NuestraSaludSegura harnesses the complementary strengths of peer navigation and mHealth. We will also test the intervention using a longitudinal group- randomized trial design assessing participants at: (1) baseline and (2) immediate post intervention. We anticipate that participants in the intervention group, relative to their counterparts in the delayed -intervention group, will demonstrate increased COVID-19 testing and vaccination. In Aim 3, we will develop and disseminate practice, research, intervention, and policy priorities and recommendations to increase COVID-19 testing and vaccination, reduce COVID-19 disparities, and promote health equity in Spanish-speaking Latinx communities by conducting an empowerment theory-based community forum. This CBPR study will advance prevention science and practice through increased understanding of the SEBI of COVID-19 testing and vaccination and testing an innovative intervention to promote and support COVID-19 testing and vaccination among a particularly underserved and vulnerable population – Spanish-speaking Latinx communities in the United States.