Table 2.
Protective efficacy due to natural exposure to SARS-CoV-2
|
SARS-CoV-2-naive individuals (n=7331) |
SARS-CoV-2-exposed individuals (n=7339) |
Protective efficacy (95% CI)* | ||||
|---|---|---|---|---|---|---|
| Cumulative follow-up in person-years† | Number of patients with an event | Cumulative follow-up in person-years† | Number of patients with an event | |||
| Any severity rtPCR-confirmed COVID-19‡ | 1088·9 | 353 | 1192·5 | 65 | 83·2% (78·0 to 87·3) | |
| Moderate-to-severe rtPCR-confirmed COVID-19 | 1088·9 | 73 | 1192·5 | 6 | 92·5% (82·9 to 97·3) | |
| Severe rtPCR-confirmed COVID-19‡ | 1088·9 | 10 | 1192·5 | 0 | 100% (59·3 to 100) | |
| Protective efficacy endpoints against rtPCR-confirmed COVID-19 due to specific identified variants | ||||||
| Alpha variant (B.1.1.7) | 1088·9 | 19 | 1192·5 | 0 | 100% (80·4 to 100) | |
| Beta variant (B.1.351, B.135.2, B.1.351.3) | 1088·9 | 23 | 1192·5 | 7 | 72·2% (33·1 to 89·9) | |
| Delta variant (B.1.617.2) | 1088·9 | 72 | 1192·5 | 18 | 77·2% (61·3 to 87·2) | |
| Gamma variant (P.1; P.1.1; P.1.2) | 1088·9 | 43 | 1192·5 | 3 | 93·6% (80·1 to 98·7) | |
| Mu variant (B.1.621) | 1088·9 | 60 | 1192·5 | 5 | 92·4% (81·2 to 97·6) | |
| Lambda variant (C.37) | 1088·9 | 7 | 1192·5 | 0 | 100% (36·7 to 100) | |
| B.1.623 variant | 1088·9 | 8 | 1192·5 | 1 | 88·6% (14·9 to 99·7) | |
| Other | 1088·9 | 121 | 1192·5 | 31 | 76·6% (65·1 to 84·8) | |
*
95% CI for protective efficacy was calculated using the Clopper-Pearson method, which was based on conditional binomial distribution.
†
Cumulative follow-up was calculated for all participants at risk within each group using the time period from 1 day after the first dose to analysis cutoff on Aug 10, 2021.
‡
Protective efficacy due to natural immunity in placebo recipients with evidence of previous exposure to SARS-CoV-2.