Table 1.
Vaccine effectiveness of BNT162b2 and CoronaVac against COVID-19 infection, COVID-19–related hospitalization, and COVID-19–related death using a retrospective cohort design
| Exposure | Events | Time to events, d, median (IQR) | Follow-up time, person-years | Incidence, 100 person-years, (95% CI) | Adjusted IRRa | P value |
|---|---|---|---|---|---|---|
|
COVID-19 infection | ||||||
| Nonvaccinated | 4933 | 157 (34–220) | 10,830.67 | 45.55 (44.28–46.84) | Ref | — |
| BNT162b2 | 2714 | 156.5 (51–201) | 10,608.71 | 25.58 (24.63–26.56) | 0.62 (0.59–0.66) | <0.001 |
| CoronaVac |
5048 |
120.5 (26–186) |
13,260.88 |
38.07 (37.02–39.13) |
0.96 (0.92–1.00) |
0.05 |
|
COVID-19 hospitalization | ||||||
| Nonvaccinated | 1488 | 154 (34–217.25) | 11,028.46 | 13.49 (12.82–14.2) | Ref | — |
| BNT162b2 | 293 | 84 (26–175) | 10,767.85 | 2.72 (2.42–3.05) | 0.36 (0.31–0.43) | <0.001 |
| CoronaVac |
620 |
61 (19.75–160) |
13,536.92 |
4.58 (4.23–4.96) |
0.56 (0.51–0.63) |
<0.001 |
|
COVID-19 death | ||||||
| Nonvaccinated | 792 | 144 (35–211.25) | 11,101.85 | 7.13 (6.65–7.65) | Ref | — |
| BNT162b2 | 49 | 94 (34–196) | 10,785.68 | 0.45 (0.34–0.6) | 0.14 (0.10–0.20) | <0.001 |
| CoronaVac | 177 | 80 (29–166) | 13,569.68 | 1.3 (1.12–1.51) | 0.30 (0.25–0.36) | <0.001 |
CI, confidence interval; COVID-19: coronavirus disease 2019; IQR, interquartile range; IRR, incidence rate ratio.
a
Vaccine effectiveness = (1 – IRR) × 100%.