TABLE 1.
Demographic characteristics of vaccine breakthrough cases compared to controls and factors associated with vaccine breakthrough in multivariable logistic regression analysis
| All (n = 414) |
Controls (n = 378) | Cases (n = 36) | OR a (95% CI) | P value | Adjusted OR b (95% CI) | P value | |
|---|---|---|---|---|---|---|---|
| Age | |||||||
| 20–29 | 78 (18.8%) | 70 (18.5%) | 8 (22.2%) | 1 (ref) | 0.396 | 1 (ref) | 0.456 |
| 30–39 | 86 (20.8%) | 78 (20.6%) | 8 (22.2%) | 0.90 (0.31–2.56) | 0.99 (0.34–2.86) | ||
| 40–49 | 109 (26.3%) | 97 (25.7%) | 12 (33.3%) | 1.08 (0.43–2.89) | 1.26 (0.49–3.44) | ||
| 50–59 | 97 (23.4%) | 93 (24.6%) | 4 (11.1%) | 0.38 (0.10–1.24) | 0.45 (0.11–1.51) | ||
| 60+ | 44 (10.6%) | 40 (10.6%) | 4 (11.1%) | 0.88 (0.22–2.96) | 1.19 (0.30–4.20) | ||
| Sex | |||||||
| Female | 310 (74.9%) | 280 (74.1%) | 30 (83.3%) | 1 (ref) | 0.203 | 1 (ref) | 0.078 |
| Male | 104 (25.1%) | 98 (25.9%) | 6 (16.7%) | 0.57 (0.21–1.32) | 0.46 (0.17–1.08) | ||
| Ethnicity (self-reported) | |||||||
| White | 298 (84.4%) | 270 (83.6%) | 28 (93.3%) | 1 (ref) | 0.265 | − | − |
| Asian | 37 (10.5%) | 36 (11.1%) | 1 (3.3%) | 0.27 (0.02–1.32) | − | ||
| Other | 18 (5.1%) | 17 (5.3%) | 1 (3.3%) | 0.57 (0.03–2.93) | − | ||
| Unreported | 61 | 55 | 6 | − | − | ||
| BMI (kg/m2 ) | |||||||
| Not obese (<30) | 162 (89.5%) | 150 (89.8%) | 12 (85.7%) | 1 (ref) | 0.645 | − | − |
| Obese (≥30.0) | 19 (10.5%) | 17 (10.2%) | 2 (14.3%) | 1.47 (0.22–6.01) | − | ||
| Unreported | 233 | 211 | 22 | − | − | ||
| Vaccine type | |||||||
| BNT162b2 | 336 (81.2%) | 310 (82.0%) | 26 (72.2%) | 1 (ref) | 0.171 | − | − |
| AZD1222 | 78 (18.8%) | 68 (18.0%) | 10 (27.8%) | 1.75 (0.77–3.71) | − | ||
| Infection history | |||||||
| Naïve | 244 (58.9%) | 214 (56.6%) | 30 (83.3%) | 1 (ref) | 0.001 | 1 (ref) | 0.0009 |
| Previous SARS-CoV-2 | 170 (41.1%) | 164 (43.4%) | 6 (16.7%) | 0.26 (0.10–0.60) | 0.25 (0.09–0.58) | ||
a
Crude odds ratio derived from single logistic regression.
b
Adjusted odds ratio derived from multiple logistic regression. The final model included and adjusted for age, sex, and infection history.