Association of Vaccine Uptake and COVID-19 Infections among nursing home staff and residents in Missouri, United States

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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was partially funded by the Sinquefield Center for Applied Economic Research ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: IRB approval was sought, approved, and determined to be exempt given all data used is publically available, including COVID-19 case reports and rates made available by the Centers for Medicare and Medicaid Services and the Missouri Department of Health and Senior and Services. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data used within this study is publically available and has been thoroughly cited.