SARS-CoV-2 vaccination and associated risk of SARS-CoV-2 infection, or severe COVID-19 (hospitalisation or death)—each assessed starting at least 14 days after the first vaccination, among the entire cohort. Data are presented by time-varying exposure after first vaccination versus unvaccinated (upper blue), as well as by first-vaccination type versus unvaccinated (lower maroon)
| Study outcome | Exposure state* | No. person-days of follow-up* | No. with outcome (rate per 10 000 person-days) | Unadjusted HR (95% CI) | Adjusted HR (95% CI)† |
| SARS-CoV-2 infection | Unvaccinated (N=2 464 998) | 303 209 192 | 51 187 (1.69) | 1.00 (referent) | 1.00 (referent) |
| Vaccinated (N=1 743 916) | 93 324 805 | 4995 (0.54) | 0.38 (0.37 to 0.39) | 0.46 (0.45 to 0.48) | |
| Severe COVID-19‡ | Unvaccinated (N=2 464 998) | 307 438 194 | 2890 (0.09) | 1.00 (referent) | 1.00 (referent) |
| Vaccinated (N=1 743 916) | 93 575 031 | 491 (0.05) | 0.71 (0.64 to 0.79) | 0.29 (0.26 to 0.33) | |
| SARS-CoV-2 infection | Unvaccinated (N=2 464 998) | 303 209 192 | 51 187 (1.69) | 1.00 (referent) | 1.00 (referent) |
| Adenovirus-vectored (N=143 358) | 8 263 735 | 434 (0.53) | 0.39 (0.36 to 0.43) | 0.49 (0.44 to 0.54) | |
| Modified RNA (N=1 600 524) | 85 059 246 | 4561 (0.54) | 0.38 (0.37 to 0.39) | 0.46 (0.44 to 0.47) | |
| Severe COVID-19 | Unvaccinated (N=2 464 998) | 307 438 194 | 2890 (0.09) | 1.00 (referent) | 1.00 (referent) |
| Adenovirus-vectored (N=143 358) | 8 284 162 | 27 (0.03) | 0.46 (0.31 to 0.68) | 0.29 (0.20 to 0.43) | |
| Modified RNA (N=1 600 524) | 85 289 045 | 464 (0.05) | 0.73 (0.66 to 0.82) | 0.29 (0.26 to 0.33) |
*Exposure is time-varying, therefore, some individuals may have contributed time as unvaccinated, and then subsequently, as vaccinated.
†Adjusted for age, sex, rural residence, area income quintile—each at baseline—as well as prior diabetes mellitus, malignancy, heart failure, cardiac ischaemia or arrhythmia, chronic kidney disease or venous thromboembolism.
‡In the vaccinated and unvaccinated groups, respectively, there were 21 deaths (0.02 per 100 000 person-days) and 133 deaths (0.04 per 100 000 person-days), from 1 day before, up to 3 days after, an SARS-CoV-2 positive PCR test, with a corresponding adjusted HR of 0.24 (95% CI 0.14 to 0.41).