Did the health care vaccine mandate work? An evaluation of the impact of the COVID-19 vaccine mandate on vaccine uptake and infection risk in a large cohort of Canadian health care workers

Abstract

We aimed to evaluate the impact of healthcare vaccine mandates on vaccine uptake and infection risk in a cohort of Canadian healthcare workers (HCWs). We conduct interrupted time series analysis through a regression discontinuity in time approach to estimate the immediate and delayed impact of the mandate. Multilevel mixed effect modeling fitted with restricted maximum likelihood was used to estimate impact on infection risk. The immediate and sustained effects of the mandate was a 0.19% (P<.05) and a 0.012% (P<.05) increase in the daily proportion of unvaccinated HCWs getting their first dose, respectively. An additional 623 (95% confidence interval: 613-667) HCWs received first doses compared to the predicted uptake absent the mandate. Adjusted test positivity declined by 0.053% (95% confidence interval: 0.035%,0.069) for every additional day the mandate was in effect. Our results indicate that the mandate was associated with significant increases in vaccine uptake and infection risk reduction in the cohort. Given the benefit that vaccination could bring to HCWs, understanding strategies to enhance uptake is crucial for bolstering health system resilience, but steps must be taken to avert approaches that sacrifice trust, foster animosity, or exacerbate staffing constraints for short-term results.