Table 3.
Incidence rates of positive SARS-CoV-2 PCR tests in vaccinated and 1-to-1 propensity-matched unvaccinated cohorts and corresponding vaccine effectiveness
| Vaccine | Time period | Vaccinated incidence rate: Cases/person-days [per 1,000 person-days] (no. of individuals contributing) | Unvaccinated incidence rate: Cases/person-days [per 1,000 person-days] (no. of individuals contributing) | Incidence rate ratio (95% CI) | Vaccine effectiveness (95% CI) |
|---|---|---|---|---|---|
| BNT162b2 | on or after 7 days following first dose | 401/2,942,986. [0.14] (n = 50,474) | 1,232/2,851,069. [0.43] (n = 50,162) | 0.32 (0.28, 0.35) | 68.5% (64.7%, 71.9%) |
| on or after 14 days following first dose | 211/2,595,549. [0.081] (n = 48,305) | 960/2,506,231. [0.38] (n = 47,863) | 0.21 (0.18, 0.25) | 78.8% (75.3%, 81.8%) | |
| on or after 7 days following first dose and prior to second dose | 293/766,978. [0.38] (n = 50,474) | 534/761,511. [0.7] (n = 50,162) | 0.54 (0.47, 0.63) | 45.5% (37.1%, 52.9%) | |
| on or after 14 days following first dose and prior to second dose | 103/419,541. [0.25] (n = 48,305) | 262/416,673. [0.63] (n = 47,863) | 0.39 (0.31, 0.49) | 61.0% (50.8%, 69.2%) | |
| on or after 7 days following the second dose | 82/1,914,500. [0.043] (n = 35,990) | 563/1,828,466. [0.31] (n = 35,011) | 0.14 (0.11, 0.18) | 86.1% (82.4%, 89.1%) | |
| on or after 14 days following the second dose | 59/1,670,896. [0.035] (n = 33,963) | 468/1,591,900. [0.29] (n = 32,910) | 0.12 (0.09, 0.16) | 88.0% (84.2%, 91.0%) | |
| mRNA-1273 | on or after 7 days following first dose | 97/946,890. [0.1] (n = 16,369) | 303/927,716. [0.33] (n = 16,309) | 0.31 (0.25, 0.4) | 68.6% (60.5%, 75.3%) |
| on or after 14 days following first dose | 49/833,098. [0.059] (n = 15,985) | 241/814,413. [0.3] (n = 15,896) | 0.2 (0.14, 0.27) | 80.1% (72.9%, 85.7%) | |
| On or after 7 days following first dose and prior to second dose | 88/369,195. [0.24] (n = 16,369) | 181/366,881. [0.49] (n = 16,309) | 0.48 (0.37, 0.63) | 51.7% (37.3%, 63.0%) | |
| on or after 14 days following first dose and prior to second dose | 40/255,403. [0.16] (n = 15,985) | 119/253,578. [0.47] (n = 15,896) | 0.33 (0.23, 0.48) | 66.6% (51.9%, 77.3%) | |
| on or after 7 days following the second dose | 7/495,550. [0.014] (n = 11,612) | 101/478,322. [0.21] (n = 11,332) | 0.067 (0.026, 0.14) | 93.3% (85.7%, 97.4%) | |
| on or after 14 days following the second dose | 6/417,664. [0.014] (n = 10,610) | 75/402,416. [0.19] (n = 10,318) | 0.077 (0.027, 0.18) | 92.3% (82.4%, 97.3%) |
Incidence is calculated as the number of individuals with at least one positive SARS-CoV-2 PCR test per 1,000 person-days. Time period: time period relative to the first vaccine dose for the vaccinated cohort or study enrollment day for the unvaccinated cohort. Vaccinated incidence rate: number of individuals with positive PCR tests in the vaccinated cohort in the time period, divided by the number of at-risk person-days for the vaccinated cohort in the time period; in brackets, the number of cases per 1,000 person-days. Unvaccinated incidence rate: number of individuals with positive PCR tests in the propensity-matched unvaccinated cohort in the time period, divided by the number of at-risk person-days for the propensity-matched unvaccinated cohort in the time period; in brackets, the number of cases per 1,000 person-days. Incidence rate ratio: vaccinated incidence rate divided by unvaccinated incidence rate along with the exact 95% CI.16 Vaccine effectiveness: 100% × (1 − incidence rate ratio) along with the 95% CI. See also Figure S5.