PROJECT SUMMARY During the pandemic, with social isolation and grief as drivers, alcohol consumption is increasing. SARS-CoV-2 itself has substantial impact on the central nervous system. When two such important public health menaces intersect, it is crucial to understand their interaction and potential synergy. In this project titled “Characterize multifaceted interactions between COVID-19 and alcohol use disorder based on real-time analysis of electronic health records of 62 million adult patients”, we propose to: 1) characterize susceptibility to COVID-19 in patients with alcohol use disorder (AUD) (“AUD → COVID-19”), consider racial and gender disparity, and follow its evolution over time; 2) characterize how COVID-19 infection and the social pandemic context impact the risk of AUD (“COVID-19 plus pandemic context → AUD”), consider racial and gender disparity, and follow these changes over time; and 3) characterize prevalence of major psychiatric disorders, other substance use disorders and severe outcomes among patients with both AUD and COVID-19 (“AUD+COVID-19 → outcomes”) and to follow these outcomes over time. Our studies will identify potential areas for timely interventions to protect patients or mitigate the worst effects of COVID-19 pandemic and AUD, singly and combined. This is especially important if there should be another surge with a virus variant, or if vaccine hesitancy is greater in those with AUD. It will also inform such studies if we have another pandemic with another organism, for the approaches we pioneer in these studies using nation-wide database of electronic health records may pave the way for rapid, real-time analytics and results to inform our control measures.