Increases in vaccination rates among nursing home staff prior to the Omicron wave were found to be associated with decreases in COVID-19-related mortality and incident diagnoses among residents and fewer incident diagnoses among staff. These study results were published in JAMA Network Open.
This longitudinal study was conducted between May 2021 and January 2022 in the United States. Researchers analyzed COVID-19 outcomes in Medicare and Medicaid-certified nursing homes within the National Healthcare Safety Network. The primary outcomes were the number of incident diagnoses and deaths among residents and the number of incident diagnoses among staff within a 1-week period. The treatment variable was the weekly rate of primary 2-dose COVID-19 vaccination among staff at each nursing care facility. A multivariate regression model was used to determine the association between staff vaccination status and resident outcomes.
There were 15,042 nursing homes included in this study, with an overall mean (SD) staff vaccination rate of 66.05% (20.36%). The nursing homes were located in counties with an overall mean (SD) weekly prevalence of incident COVID-19 of 0.25 (0.49) per 1000 people.
The researchers discovered that a 10% increase in weekly staff vaccination rates was associated with a decrease (per 1000 residents) in both weekly COVID-19 incidence (0.13; 95% CI, -0.20 to -0.10; P =.002) and mortality (0.02; 95% CI, -0.03 to -0.01; P =.003) among residents. The number of incident diagnoses among staff also decreased for each 10% increase in the weekly staff vaccination rate (0.03; 95% CI, -0.04 to -0.02; P <.001).
Further analysis showed incident COVID-19 diagnoses and deaths among residents and incident diagnoses among staff decreased more significantly when vaccination uptake among staff reached 60% and 80%. Of note, increases in staff vaccination rates were associated with worse COVID-19 outcomes up until staff vaccination uptake reached 30%. Thereafter, a correlation between higher vaccination rates among staff and improved COVID-19 outcomes was observed, suggesting the benefits of vaccination.
Limitations of this study include the inability to establish a causal estimate for the effect of staff vaccination rates on COVID-19 outcomes. The researchers were also unable to control for potential confounders, such as booster dose uptake and adherence to COVID-19 protocols.
According to the researchers “Policy makers may want to consider longer-term policy options to increase the uptake of booster doses among staff in nursing homes.”
Sinha S, Konetzka RT. “Association of COVID-19 vaccination rates of staff and COVID-19 illness and death among residents and staff in US nursing homes.” JAMA Netw Open. 2022;5(12):e2249002. doi:10.1001/jamanetworkopen.2022.49002