The Relationship of Vaccine Uptake and COVID-19 Infections among Nursing Home Staff and Residents in Missouri

Nursing homes (NH) continue to struggle with COVID-19 morbidity and mortality with older adult residents at greater risk of infection due to proximity to other residents, advanced aging-related chronic illnesses, and contact with staff. While many states have prioritized COVID-19 vaccinations among older adults, vaccinations among NH staff vary. The purpose of this study was to quantify the relationship between nursing home staff vaccination uptake and COVID-19 infections among residents. A zero-inflated Poisson regression model was constructed to predict the weekly number of COVID-19 cases among Missouri nursing home residents using data from the Centers for Medicaid and Medicare Services. A total of 1,124 COVID-19 infections were reported among 504 NH residents between January 1, 2021 and August 22, 2021. After adjusting for number of total residents, resident vaccine rate, staff quality rating, and respective county COVID-19 rate, for every percent increase in nursing home staff vaccine rate the risk of COVID-19 infections significantly decreased by 13% (IRR 0.87, 95% CI 0.81, 0.93). This study identified that NH staff, likely due to greater mobility, are important to prioritize in vaccination efforts to protect themselves and residents of their facilities from COVID-19 infections. Further, the CMS staff ratings were significant predictors of infection as well, which highlight the structural challenges that exist within and outside the context of a highly infectious and deadly pandemic. These results also provide insights to optimizing vaccination roll-out to best protect our communities most vulnerable residents.