Collision of Alzheimers disease and COVID-19 pandemic in the United States: risks, outcomes, disparities and treatments - PROJECT SUMMARY In this project titled “Collision of Alzheimer’s disease and COVID-19 pandemic in the United States: risks, outcomes, disparities and treatments”, we propose to: 1) examine COVID-19 risk in patients with Alzheimer’s disease (AD), consider racial and gender disparity, and follow its evolution over time; 2) examine new onset of AD in COVID-19 survivors, consider racial and gender disparity, and follow these changes over time; 3) characterize long-haul neuropsychiatric Post-Acute Sequelae of COVID-19 (Neuro-PASC) in COVID- 19 survivors with AD, consider racial and gender disparity, and follow these changes over time; and 4) investigate therapeutic effects of Tumor Necrosis Factor (TNF) blockers on overall mortality and long-haul Neuro-PASC in COVID-19 survivors with AD. To answer these questions, we will utilize a US nation-wide, real- time database of de-identified electronic health records (EHRs) of 80 million patients (4.8 million confirmed COVID-19 cases). Our study will primarily focus on over 17 million senior patients age ³ 65 years, including more than 1 million COVID-19 cases, 265,818 patients diagnosed with AD, and 22,518 patients with both COVID-19 and AD (as of May 20, 2021). Our study will establish methods for real-time analysis of EHRs of vulnerable aging population of tens of millions across the USA in examining infectious diseases and their interaction with existing disorders such as AD, which will allow us to be better prepared should another pandemic overtake us. The significance of these studies therefore extends beyond the data at hand.