Table 2.
Main analysis; adjusted Third Dose Effectiveness (VE) against SARS-Cov2 infection.
| Exposure Groups/Booster Period | Cases | Controls | Adjusted Third Dose VE (%) for SARS-Cov2 Infection (CI 95%) |
|---|---|---|---|
| Aug. 2021 (−5)‡ | 21,777 | 21,234 | Reference |
| Sep. 2021 (−4)‡ | 25,419 | 24,432 | 3.6 (0.6, 6.5) |
| Oct. 2021 (−3)‡ | 7050 | 7773 | 16.5(13, 19.9) |
| Nov. 2021 (−2)‡ | 792 | 1156 | 35.7(29.8, 41.2) |
| Dec. 2021 (−1)‡ | 421 | 864 | 53.4(47.7, 58.6) |
| 55459 | 55459 |
‡ Denotes the months prior to the outcome period. Therefore, those who received the booster in October 2021, received the third dose 3 months prior to the outcome period.
VE was defined as 100%*[1-(Odds Ratio)] for each of the month-since-vaccination categories.
ORs were estimated with conditional logistic regression on a 1:1 matched dataset, and adjusted for comorbidities.