Table 1.
Effect of partial and complete vaccination on selected outcomes measured according with data accumulated during the first five months since starting the campaign (please see text, Question 3).
| # Events | Vaccine Status | HR | (95% CI) | Vaccine Effectiveness | |
|---|---|---|---|---|---|
| Positivity to nasopharyngeal swap | 291,128 | Partial | 0.161 | (0.159 to 0.164) | 84% |
| Full | 0.100 | (0.098 to 0.103) | 90% | ||
| Admission to ordinary hospital ward | 35,736 | Partial | 0.100 | (0.096 to 0.104) | 90% |
| Full | 0.031 | (0.029 to 0.033) | 97% | ||
| Admission to intensive care unit | 3450 | Partial | 0.033 | (0.027 to 0.040) | 97% |
| Full | 0.008 | (0.005 to 0.013) | 99% | ||
| Death | 6956 | Partial | 0.073 | (0.067 to 0.081) | 93% |
| Full | 0.009 | (0.007 to 0.011) | 99% |
Footnote. The analysis was based on the cohort of 2,351,853 potential vaccine recipients who on 31 May 2021 received at least one dose of vaccine at a given date (index date), and on as many 1:1 matched recipients who on the index date had not yet received any vaccine dose. Cox proportional hazard models were used for separately estimating the hazard ratio (HR) of selected outcomes, together with its 95% confidence interval (CI), associated with the time-dependent partial of full exposure to vaccine. Vaccine effectiveness was measured as complementary to the HR. The model was adjusted for available demographic and clinical characteristics.