Table 4.
Vaccine efficacy of one dose of SCB-2019 in participants with evidence of previous exposure to SARS-CoV-2.
|
SCB-2019 (n=7353) |
Placebo (n=7339) |
Vaccine efficacy (95% CI)* | |||||
|---|---|---|---|---|---|---|---|
| Number of individuals at risk | Cumulative follow-up in person-years† | Number of individuals with event | Number of individuals at risk | Cumulative follow-up in person-years† | Number of individuals with event | ||
| Any severity rtPCR-confirmed COVID-19 | 7325 | 419·9 | 14 | 7305 | 421·1 | 28 | 49·9% (1·5 to 75·6) |
| Moderate-to-severe rtPCR-confirmed COVID-19 | 7325 | 419·9 | 3 | 7305 | 421·1 | 3 | −0·3% (−649·0 to 86·6) |
| Severe rtPCR-confirmed COVID-19 | 7325 | 419·9 | 0 | 7305 | 421·1 | 0 | − |
Vaccine efficacy endpoints (from 14 days after the first dose up to second dose) of the cut-off data for efficacy analysis. Participants included in the analysis population were considered at risk only if they were followed ≥14 days after the first or second dose in the corresponding vaccine efficacy analysis period.
*
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.