Table 4. Effectiveness of the BNT162b2 Vaccine against Symptomatic SARS-CoV-2 Infection and Asymptomatic SARS-CoV-2 Infection.
| Substudies* | Effectiveness against Symptomatic Infection† | Effectiveness against Asymptomatic Infection‡ | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Case Participants: PCR-Positive§ |
Controls: PCR-Negative§ |
Effectiveness % (95% CI)¶ | Case Participants: PCR-Positive§ |
Controls: PCR-Negative§ |
Effectiveness % (95% CI)¶ | |||||
| Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | Vaccinated | Unvaccinated | |||
| 0–13 Days after first dose | 1954 | 38,814 | 1864 | 38,904 | −5.5 (−12.9 to 1.4) |
984 | 26,988 | 962 | 27,010 | −2.6 (−12.8 to 6.7) |
| ≥14 Days after first dose and no second dose | 1074 | 39,187 | 1922 | 38,339 | 47.9 (43.6 to 51.9) |
516 | 26,968 | 645 | 26,839 | 22.2 (12.1 to 31.2) |
| Month after second dose | ||||||||||
| 1 | 867 | 40,271 | 3756 | 37,382 | 81.5 (79.9 to 83.0) |
781 | 27,102 | 2202 | 25,681 | 73.1 (70.3 to 75.5) |
| 2 | 650 | 39,402 | 1948 | 38,104 | 72.5 (69.6 to 75.1) |
381 | 27,038 | 899 | 26,520 | 66.9 (61.9 to 71.3) |
| 3 | 372 | 39,030 | 1040 | 38,362 | 70.6 (66.4 to 74.3) |
239 | 26,982 | 402 | 26,819 | 47.7 (37.3 to 56.3) |
| 4 | 258 | 38,829 | 486 | 38,601 | 57.0 (48.6 to 64.0) |
120 | 26,956 | 132 | 26,944 | 11.5 (−17.1 to 33.2) |
| 5 | 316 | 38,776 | 344 | 38,748 | 12.0 (−6.1 to 27.1) |
99 | 26,956 | 117 | 26,938 | 24.3 (−7.1 to 46.5) |
| 6 | 230 | 38,800 | 251 | 38,779 | 12.8 (−9.1 to 30.3) |
125 | 26,958 | 124 | 26,959 | −2.1 (−52.0 to 31.4) |
| ≥7 | 75 | 38,761 | 97 | 38,739 | 27.8 (−1.4 to 48.7) |
29 | 26,948 | 25 | 26,952 | −33.3 (−181.8 to 36.9) |
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, have been included in the corresponding estimate of vaccine effectiveness. Thus, the number of case participants (and controls) varied across time-since-vaccination analyses.
A symptomatic infection was defined as a PCR-positive test conducted because of clinical suspicion due to the presence of symptoms compatible with a respiratory tract infection.
An asymptomatic infection was defined as a PCR-positive test conducted with no reported presence of symptoms compatible with a respiratory tract infection — that is, the PCR testing was done as part of a survey or a random testing campaign.
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.