Figure 1.

Kaplan–Meier failure curves of healthcare workers by COVID-19 vaccination status, Treviso province, Italy, 3 January–24 March 2021 (n = 6,331)^a

COVID-19: coronavirus disease; HCW: healthcare workers; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.

^a The follow-up analysis was started on day 7 from the start of the vaccination campaign when the number of vaccinated HCW was sufficiently high to allow robust estimates [10].

Shaded bands delimit 95% confidence intervals. Data reported under the panels indicate the number of HCW at risk of infection at the start of each time interval and the number of infections (in brackets) that occurred within the time interval. Data are presented separately for unvaccinated HCW and those who received at least one dose of the vaccine.