Table 3. Sensitivity Analysis.*.
| Substudies† | Effectiveness against Infection | Effectiveness against Hospitalization and Death | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Case Participants: PCR-Positive‡ |
Controls: PCR-Negative‡ |
Effectiveness % (95% CI)§ | Case Participants: Severe, Critical, or Fatal Disease‡¶ |
Controls: PCR-Negative‡ |
Effectiveness % (95% CI)§ | |||||
| Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | |||
| 0–13 Days after first dose | 4228 | 111,098 | 4053 | 111,273 | −11.9 (−17.3 to −6.7) |
245 | 4001 | 286 | 3960 | 7.5 (−11.9 to 23.6) |
| ≥14 Days after first dose and no second dose | 2358 | 111,472 | 3567 | 110,263 | 32.2 (28.2 to 35.9) |
102 | 4032 | 272 | 3862 | 65.0 (55.0 to 72.8) |
| Month after second dose | ||||||||||
| 1 | 2915 | 112,998 | 9986 | 105,927 | 75.8 (74.6 to 77.0) |
32 | 4082 | 585 | 3529 | 95.9 (93.6 to 97.3) |
| 2 | 1450 | 111,874 | 4304 | 109,020 | 69.7 (67.4 to 71.8) |
23 | 4062 | 323 | 3762 | 96.3 (92.9 to 98.0) |
| 3 | 800 | 111,388 | 2128 | 110,060 | 63.7 (59.9 to 67.1) |
17 | 4026 | 181 | 3862 | 93.4 (87.5 to 96.5) |
| 4 | 492 | 111,070 | 856 | 110,706 | 39.1 (29.9 to 47.0) |
10 | 3996 | 51 | 3955 | 80.8 (56.9 to 91.4) |
| 5 | 548 | 110,991 | 646 | 110,893 | 11.4 (−3.5 to 24.1) |
0 | 3990 | 33 | 3957 | 100.0‖ |
| 6 | 460 | 111,007 | 512 | 110,955 | 9.2 (−9.1 to 24.5) |
8 | 3988 | 24 | 3972 | 81.8 (18.5 to 95.9) |
| ≥7 | 135 | 110,942 | 162 | 110,915 | −4.4 (−41.3 to 22.9) |
6 | 3983 | 11 | 3978 | 44.1 (−86.5 to 83.3) |
Shown is the effectiveness of the BNT162b2 vaccine against any SARS-CoV-2 infection and against any severe, critical, or fatal case of COVID-19 after adjustment for previous infection and health care worker status.
In each analysis for a specific time-since-vaccination stratum, we included only participants vaccinated in this specific time-since-vaccination stratum and those unvaccinated. Only matched pairs of PCR-positive and PCR-negative persons, in which both members of the pair were either unvaccinated or fell within each time-since-vaccination stratum, were included in the corresponding estimate of vaccine effectiveness. Thus, the number of case participants (and controls) varied across time-since-vaccination analyses.
Case participants and controls were matched one to one according to sex, 10-year age group, nationality, reason for PCR testing, and calendar week of PCR test.
Vaccine effectiveness was estimated with the use of the test-negative, case–control study design.11,12
Severity,21 criticality,21 and fatality22 were defined according to World Health Organization guidelines.
The confidence interval could not be estimated because there were zero events among vaccinated participants.