Table 3.
VE of any vaccine in preventing SARS-CoV-2 Omicron BA.2 variant infection.
| Variables | Cases (N = 414) |
Controls (N = 828) |
Crude OR (95% CI) |
Adjusted ORa (95% CI) |
Adjusted VE, % (95% CI) |
||
|---|---|---|---|---|---|---|---|
| n | % | n | % | ||||
| Unvaccinated | 29 | 7.0 | 37 | 4.5 | |||
| With any vaccine | 385 | 93.0 | 791 | 95.5 | 0.621 (0.376–1.025) | 0.650 (0.387–1.091) | 35.0 (−9.1–61.3) |
| Partial vaccination | 10 | 2.4 | 10 | 1.2 | 1.276 (0.468–3.476) | 1.311 (0.476–3.611) | −31.1 (−261.1–52.4） |
| Full vaccination | 243 | 58.7 | 445 | 53.7 | 0.697 (0.418–1.161) | 0.689 (0.408–1.161) | 31.1 (−16.1–59.2) |
| Booster vaccination | 132 | 31.9 | 336 | 40.6 | 0.501 (0.296–0.848) | 0.484 (0.276–0.848) | 51.6 (15.2–72.4) |
| Vaccine typeb | |||||||
| Inactivated vaccine | 303 | 73.2 | 626 | 75.6 | 0.618 (0.373–1.023) | 0.645 (0.383–1.086) | 35.5 (−8.6–61.7) |
| Recombinant protein vaccine | 68 | 16.4 | 106 | 12.8 | 0.818 (0.461–1.453) | 0.870 (0.430–1.761) | 13.0 (−76.1–57.0) |
| Ad5-nCoV vaccine | 10 | 2.4 | 39 | 4.7 | 0.327 (0.140–0.764) | 0.342 (0.134–0.872) | 65.8 (12.8–86.6) |
| Genderc | |||||||
| Male | 151 | 36.5 | 412 | 49.8 | 1.008 (0.439–2.312) | 1.075 (0.461–2.507) | −7.5 (−150.7–53.9) |
| Female | 234 | 56.5 | 379 | 45.8 | 0.441 (0.223–0.873) | 0.449 (0.223–0.904) | 55.1 (9.6–77.7) |
| Age group (years)d | |||||||
| 0–59 | 318 | 76.8 | 659 | 79.6 | 0.612 (0.360–1.042) | 0.615 (0.359–1.053) | 38.5 (−5.3–64.1) |
| ≥60 | 67 | 16.2 | 132 | 15.9 | 0.677 (0.147–3.112) | 0.670 (0.145–3.093) | 33.0 (−209–85.5) |
| Time since last dose vaccination (months) | |||||||
| 0–6 | 186 | 44.9 | 474 | 57.2 | 0.501 (0.299–0.838) | 0.532 (0.313–0.904) | 46.8 (9.6–68.7) |
| >6 | 199 | 48.1 | 317 | 38.3 | 0.801 (0.501–1.469) | 0.858 (0.501–1.469) | 14.2 (−46.9–49.9) |
| Type of booster vaccination | |||||||
| Homologous booster vaccination | 128 | 30.9 | 316 | 38.2 | 0.517 (0.305–0.876) | 0.236 (0.065–0.857) | 51.8 (9.6–74.3) |
| Heterologous booster vaccination | 4 | 1.0 | 20 | 2.4 | 0.255 (0.079–0.829) | 0.482 (0.257–0.904) | 76.4 (14.3–93.5) |
aORs were from univariate conditional logistic regression and were adjusted by gender and age.
bIndividuals who had received a heterologous booster vaccination were not included.
cORs were adjusted by age only. The reference groups for male and female subgroups were the corresponding populations in the unvaccinated group.
dORs were adjusted by gender only. The reference groups for 0–59 and ≥60-year-old subgroups were the corresponding populations in the unvaccinated group.