Abstract: The novel virus, SARS-CoV-2, which causes Coronavirus Disease – 2019 (COVID-19) is a significant threat to public health. SARS-CoV-2 is both highly transmissible, as is evidenced by the current pandemic, and can lead to clinically significant COVID-19 disease. In severe and critical cases SARS-CoV-2 infection causes progressive pulmonary infection, complicated by respiratory failure, with a high prevalence of acute respiratory distress syndrome. Out of all age groups, older adults have the greatest risk of experiencing severe COVID-19 disease and its associated complications (CDC 2020; Grabowski and Mor 2020). Globally, there are a number of reports of COVID-19 rapidly spreading among the residents of skilled nursing facilities. Sadly, these nursing home residents also have high associated rates of both morbidity and mortality (Arons et al. 2020; Grabowski and Mor 2020; Graham et al. 2020). In the United States (US), at least 153,000 nursing home residents and employees have contracted COVID-19 disease and account for 35% of the country’s deaths (Werner et al. 2020). With more than 1.3 million Americans living in nursing homes (CDC 2016), there is an urgent need for effective, preventative strategies. CoVPN 3501 is a randomized, double-blind, placebo-controlled, prophylaxis study to evaluate the efficacy and safety of the intravenous mAb, LY3819253, in preventing SARS-CoV-2 infection and COVID-19, compared to placebo. It is expected that 1700-2400 participants (intent-to-treat [ITT] population) will be randomly assigned to study intervention such that approximately 1300 SARS-CoV-2 negative participants are randomized in the study with the goal of achieving approximately 33 events (in each of the primary and key secondary endpoints). This study will evaluate the effectiveness and safety of a monoclonal antibody (mAb), LY3819253, in preventing SARS-CoV-2 infection and COVID-19 disease in nursing home facility staff and residents.