Table 2.
Vaccine effectiveness against COVID-19-related mortality among individuals with different vaccination status by age group.
| Vaccination status | Case | Control | Crude OR (95% CI) | Adjusted OR (95% CI) | VE % (95% CI) |
|---|---|---|---|---|---|
| Aged 65 years and above | |||||
| Unvaccinated | 4860 | 26990 | (Ref) | (Ref) | (Ref) |
| 1 dose only | |||||
| BNT162b2 | 111 | 2218 | 0.244 (0.201–0.296) | 0.265 (0.217–0.323) | 73.5 (67.7–78.3) |
| CoronaVac | 1369 | 13155 | 0.531 (0.498–0.567) | 0.584 (0.547–0.625) | 41.6 (37.5–45.3) |
| 2 doses only | |||||
| All BNT162b2 | 109 | 6121 | 0.076 (0.063–0.093) | 0.093 (0.077–0.114) | 90.7 (88.6–92.3) |
| All CoronaVac | 669 | 15140 | 0.210 (0.193–0.228) | 0.252 (0.231–0.275) | 74.8 (72.5–76.9) |
| 3 doses | |||||
| All BNT162b2 | 12 | 2700 | 0.016 (0.009–0.029) | 0.020 (0.011–0.035) | 98.0 (96.5–98.9) |
| All CoronaVac | 34 | 3794 | 0.035 (0.025–0.049) | 0.045 (0.032–0.063) | 95.5 (93.7–96.8) |
| B-B-C | 0 | 30 | – | – | – |
| C-C-B | 6 | 962 | 0.023 (0.010–0.050) | 0.028 (0.013–0.063) | 97.2 (93.7–98.7) |
| Aged 51–64 years | |||||
| Unvaccinated | 224 | 621 | (Ref) | (Ref) | (Ref) |
| 1 dose only | |||||
| BNT162b2 | 13 | 170 | 0.192 (0.106–0.348) | 0.201 (0.105–0.383) | 79.9 (61.7–89.5) |
| CoronaVac | 61 | 341 | 0.442 (0.321–0.609) | 0.513 (0.361–0.730) | 48.7 (27.0–63.9) |
| 2 doses only | |||||
| All BNT162b2 | 35 | 774 | 0.107 (0.073–0.157) | 0.124 (0.082–0.186) | 87.6 (81.4–91.8) |
| All CoronaVac | 59 | 847 | 0.167 (0.121–0.229) | 0.193 (0.137–0.272) | 80.7 (72.8–86.3) |
| 3 doses | |||||
| All BNT162b2 | 3 | 513 | 0.012 (0.004–0.039) | 0.016 (0.005–0.050) | 98.4 (95.0–99.5) |
| All CoronaVac | 4 | 420 | 0.019 (0.007–0.052) | 0.024 (0.009–0.067) | 97.6 (93.3–99.1) |
| B-B-C | 0 | 3 | – | – | – |
| C-C-B | 0 | 184 | – | – | – |
| Aged 18–50 years | |||||
| Unvaccinated | 49 | 108 | (Ref) | (Ref) | (Ref) |
| 1 dose only | |||||
| BNT162b2 | 2 | 33 | 0.145 (0.033–0.637) | 0.101 (0.017–0.614) | 89.9 (38.6–98.3) |
| CoronaVac | 7 | 42 | 0.354 (0.145–0.868) | 0.622 (0.226–1.708) | 37.8 (−70.8–77.4) |
| 2 doses only | |||||
| All BNT162b2 | 13 | 242 | 0.125 (0.063–0.249) | 0.134 (0.062–0.290) | 86.6 (71.0–93.8) |
| All CoronaVac | 9 | 121 | 0.142 (0.062–0.327) | 0.173 (0.069–0.435) | 82.7 (56.5–93.1) |
| 3 doses | |||||
| All BNT162b2 | 4 | 89 | 0.104 (0.036–0.304) | 0.134 (0.043–0.421) | 86.6 (57.9–95.7) |
| All CoronaVac | 2 | 61 | 0.064 (0.014–0.285) | 0.069 (0.013–0.362) | 93.1 (63.8–98.7) |
| B-B-C | 0 | 0 | – | – | – |
| C-C-B | 1 | 24 | 0.092 (0.012–0.723) | 0.195 (0.023–1.670) | 80.5 (−67.0–97.7) |
OR: odds ratio; VE: vaccine effectiveness; CI: confidence interval; B-B-C: two doses of BNT162b2 followed by CoronaVac; C-C-B: two doses of CoronaVac followed by BNT162b2.
Adjusted for comorbidities (cancer, chronic kidney disease, respiratory disease, diabetes, cardiovascular disease, dementia), chronic medication use in past 90 days (renin-angiotensin-system agents, beta blockers, calcium channel blockers, diuretics, nitrates, lipid lowering agents, insulins, antidiabetic drugs, oral anticoagulants, antiplatelets, immunosuppressants).