Vaccine coverage among HCWs at study phase 2
One thousand nine hundred and sixty (84.0%) HCWs of the 2,332 HCWs had known vaccination status, among them 1,743 (88.9%) HCWs had received at least one dose of the BNT162b2 vaccine by the end of February, 2021 (1,717 received two doses with a median time of 20 days between dose 1 and 2). The characteristics of the HCWs by vaccination status are presented in Table S3 .
Unvaccinated HCWs were significantly younger than vaccinated (median age: 45.9 vs 48.2 years; p = 0.002). Physicians were significantly more likely to be vaccinated than other professional groups (p < 0.001). The HCWs in non-clinical areas were less vaccinated than those working in clinical locations (85.7% vs 90.2%, p = 0.005). There were differences in the vaccination status between the wards, with HCWs working on the surgical wards being the most frequently vaccinated group (92.6%, p = 0.04). There were no significant differences in vaccination status between HCWs working in wards involved and not involved in the treatment of COVID-19 patients. The HCWs most likely to have received at least one dose of the vaccine were previously uninfected with SARS-CoV-2 (p < 0.001). Before the implementation of the vaccination programme, 352 HCWs (285 vaccinated and 67 unvaccinated) had laboratory confirmed SARS-CoV-2 infection. Unvaccinated HCWs had a shorter time period from previous infections when compared with vaccinated HCWs (median 20 vs 61 days; p < 0.001).