Table 2.
Efficacy of 2 doses of ChAdOx1 nCoV-19 against primary symptomatic COVID-19, by SARS-CoV-2 lineage.
| Lineage | ChAdOx1 nCoV-19 n (%) N = 4772 |
Control n (%) N = 4661 |
Vaccine efficacy (95% CI) |
Vaccine efficacy using multiple imputation for unavailable swabs (95% CI) |
|---|---|---|---|---|
| B.1.1.33 | 1 (0.0%) | 8 (0.2%) | 88.2 (5.4, 98.5) | |
| B.1.1.28 | 11 (0.2%) | 38 (0.8%) | 72.6 (46.4, 86.0) | |
| P.2 (Zeta) | 38 (0.8%) | 115 (2.5%) | 68.7 (54.9, 78.3) | 65.2 (52.5, 74.4) |
| P.1 (Gamma) | 5 (0.1%) | 13 (0.3%) | 63.6 (−2.1, 87.0) | 65.8 (4.9, 87.7) |
| Undetermined | 22 (0.5%) | 48 (1.0%) | 56.6 (28.2, 73.8) |
*Undetermined lineage are those where a lineage could not be assigned due to low viral load or degraded RNA.