Table 2.
Effectiveness of the BNT162b2 COVID-19 vaccine, between Dec 7, 2020, and Feb 5, 2021 (n=23 324)
| Total person-time, days | Number of PCR positives | Incidence density per 10 000 person-days | Unadjusted hazard ratio (95% CI) | Adjusted hazard ratio (95% CI) | |
|---|---|---|---|---|---|
| Full cohort | |||||
| Unvaccinated | 710 587 | 977 | 14 | 1 (ref) | 1 (ref) |
| Dose 1 | 87 278 | 71 | 8 | 0·43 (0·23–0·64) | 0·30 (0·15–0·45) |
| Dose 2 | 20 978 | 9 | 4 | 0·23 (0·06–0·40) | 0·15 (0·04–0·26) |
| Negative cohort | |||||
| Unvaccinated | 442 605 | 902 | 20 | 1 (ref) | 1 (ref) |
| Dose 1 | 59 748 | 66 | 11 | 0·33 (0·17–0·49) | 0·28 (0·14–0·42) |
| Dose 2 | 14 746 | 8 | 5 | 0·18 (0·04–0·31) | 0·14 (0·03–0·24) |
| Positive cohort | |||||
| Unvaccinated | 267 982 | 75 | 3 | .. | .. |
| Dose 1 | 27 530 | 5 | 2 | .. | .. |
| Dose 2 | 6232 | 1 | 2 | .. | .. |
We calculated cumulative vaccine effectiveness after suitable intervals (21 days post-first dose and 7 days post-second dose) to focus on infections acquired since vaccination after a sufficient interval for biological protection. Unadjusted includes vaccine effect (period) only. The full model was adjusted for site as a random effect, period, and eight fixed effects: age, gender, ethnicity, comorbidities, job role, frequency of contact with COVID-19 patients, employed in a patient facing role, and occupational exposure. There was insufficient information to model the positive cohort separately so stratified hazard ratios are not available for the positive cohort.