Table 1.
Vaccine effectiveness against COVID-19-associated hospitalization and moderate-to-severe disease with adjustment by calendar days and 14-day lag in children (aged 3–11 years, January 21, 2022 to April 19, 2022) and adolescents (aged 12–18 years, January 1, 2022 to April 19, 2022)
| Numbers of cases | Mean days elapsed since the last dose (SD) | VE estimate | 95%CI | p value | |
|---|---|---|---|---|---|
| VE against hospitalization | |||||
| Children (aged 3–11 years) | |||||
| BNT162b2, 1 dose | 12 | 27.4 (14.7) | 65.6% | 38.2–82.5 | 0.0008 |
| CoronaVac, 1 dose | 127 | 23.8 (7.5) | 13.5% | −14.0–34.6 | 0.3187 |
| CoronaVac, 2 doses | 4 | 23.3 (10.7) | 86.2% | 65.8–95.9 | 0.0001 |
| Unvaccinated | 956 | Ref. | Ref. | Ref. | Ref. |
| Adolescents (aged 12–18 years) | |||||
| BNT162b2, 1 dose | 114 | 132.2 (54.1) | 60.2% | 47.0–70.2 | <0.0001 |
| CoronaVac, 1 dose | 22 | 34.7 (16.0) | 31.0% | −9.34–58.3 | 0.1286 |
| BNT162b2, 2 doses | 165 | 171.5 (51.2) | 82.3% | 76.9–86.4 | <0.0001 |
| CoronaVac, 2 doses | 5 | 47.4 (19.6) | 90.7% | 79.2–96.8 | <0.0001 |
| Unvaccinated | 149 | Ref. | Ref. | Ref. | Ref. |
| VE against moderate-to-severe disease | |||||
| Children and adolescents (aged 3–18 years) | |||||
| BNT162b2, 1 dose | 8 | 126.1 (54.0) | 84.6% | 69.7–93.2 | <0.0001 |
| CoronaVac, 1 dose | 33 | 22.2 (5.7) | 33.7% | −4.6–58.9 | 0.0855 |
| BNT162b2, 2 doses | 8 | 185.6 (49.4) | 93.1% | 86.4–97.0 | <0.0001 |
| CoronaVac, 2 doses | 1 | 39.0 (0.0) | 95.8% | 80.7–99.8 | 0.0017 |
| Unvaccinated | 178 | Ref. | Ref. | Ref. | Ref. |
SD, standard deviation; VE, vaccine effectiveness; CI, confidence interval; Ref. reference