Table 4. Vaccine effectiveness by time since vaccination.
| Outcome |
Vaccination
history |
Duration ≤ 3 months | Duration 4−6 months | |||||
|
Percentage/% (case/total
infection) |
Unadjusted VE/%
(95% CI) |
Adjusted VE/%
(95% CI) |
Percentage/% (case/total
infection) |
Unadjusted VE/%
(95% CI) |
Adjusted VE/%
(95% CI) |
|||
| Note: “—” Means no data were available.
Abbreviations: CI=Confidence interval; VE=vaccine effectiveness. | ||||||||
| Symptomatic
disease |
Unvaccinated | 12.90 (61/473) | Ref | Ref | 12.90 (61/473) | Ref | Ref | |
| Completely primary | 4.34 (34/784) | 66.11 (46.89 to 78.37) | 52.32 (25.73 to 69.39) | 5.37 (11/205) | 67.08 (34.97 to 83.34) | 49.95 (1.20 to 74.64) | ||
| BBIBP-CorV | 5.48 (8/146) | 57.51 (13.30 to 79.18) | 39.37 (−20.41 to 69.46) | 1.54 (1/65) | 88.07 (15.41 to 98.32) | 82.00 (−25.73 to 97.42) | ||
| CoronaVac | 4.64 (9/194) | 64.03 (29.02 to 81.77) | 45.50 (−5.98 to 71.97) | 5.63 (8/142) | 56.32 (10.90 to 78.58) | 29.83 (−41.09 to 65.11) | ||
| Combined | 3.45 (8/232) | 73.26 (45.06 to 86.99) | 59.50 (18.31 to 79.92) | 0 (0/5) | — | — | ||
| Pneumonia | Unvaccinated | 10.15 (48/473) | Ref | Ref | 10.15 (48/473) | Ref | Ref | |
| Completely primary | 2.42 (19/784) | 74.16 (54.45 to 85.34) | 60.31 (31.31 to 77.07) | 3.41 (7/205) | 81.41 (49.10 to 93.21) | 67.08 (9.33 to 88.05) | ||
| BBIBP-CorV | 4.11 (6/146) | 59.51 (7.30 to 82.31) | 39.63 (−35.46 to 73.10) | 0 (0/65) | — | — | ||
| CoronaVac | 1.55 (3/194) | 84.76 (51.66 to 95.20) | 73.85 (17.91 to 91.67) | 2.82 (4/142) | 72.24 (24.35 to 89.81) | 47.41 (−44.35 to 80.84) | ||
| Combined | 2.59 (6/232) | 74.52 (41.32 to 88.93) | 61.79 (13.21 to 83.18) | 0 (0/5) | — | — | ||
| Severe case | Unvaccinated | 3.17 (15/473) | Ref | Ref | 3.17 (15/473) | Ref | Ref | |
| Completely primary | 0.26 (2/784) | 88.97 (52.03 to 97.47) | 80.64 (13.16 to 95.68) | 0.98 (2/205) | — | — | ||
| BBIBP-CorV | 0 (0/146) | — | — | 0 (0/65) | — | — | ||
| CoronaVac | 0 (0/194) | — | — | 0 (0/142) | — | — | ||
| Combined | 0.86 (2/232) | 72.81 (−17.88 to 93.73) | 61.11 (−72.65 to 91.24) | 0 (0/5) | — | — | ||