Table 2.
Matched OR and 95% CI for Bordetella pertussis infection, under- versus age-appropriately vaccinated of DTwP or DTaPa.
| Cases(n = 145) | Controls(n = 2,900) | Matched ORb | (95% CI)b | p-valueb | |
|---|---|---|---|---|---|
| Number of doses undervaccinated | |||||
| 0 | 87 (60.0) | 2,179 (75.1) | 1.0 | ||
| 1, 2, 3, or 4 | 58 (40.0) | 721 (24.9) | 2.28 | (1.57–3.31) | <0.0001 |
| 1 | 29 (20.0) | 439 (15.1) | 1.84 | (1.17–2.89) | 0.0080 |
| 2 | 12 (8.3) | 129 (4.4) | 2.80 | (1.44–5.44) | 0.0023 |
| 3 | 13 (9.0) | 113 (3.9) | 3.85 | (1.93–7.67) | 0.0001 |
| 4 | 4 (2.8) | 40 (1.4) | 3.79 | (1.19–12.07) | 0.0243 |
| Days undervaccinated | |||||
| 0 | 87 (60.0) | 2,179 (75.1) | 1.0 | ||
| 1–30 | 26 (17.9) | 370 (12.8) | 1.93 | (1.21–3.06) | 0.0057 |
| 31–90 | 13 (9.0) | 193 (6.7) | 2.06 | (1.09–3.88) | 0.0255 |
| 91–1,003 | 19 (13.1) | 158 (5.4) | 4.16 | (2.26–7.67) | <0.0001 |
| Dose number undervaccinated | |||||
| None | 87 (60.0) | 2,179 (75.1) | 1.0 | ||
| Dose 1, 2, or 3 only | 47 (32.4) | 500 (17.2) | 2.52 | (1.71–3.71) | <0.0001 |
| Dose 4 only | 5 (3.4) | 115 (4.0) | 1.02 | (0.33–3.15) | 0.9784 |
| Dose 1, 2, or 3; plus dose 4 | 6 (4.1) | 106 (3.7) | 1.35 | (0.49–3.72) | 0.5657 |
OR, odds ratio; CI, confidence interval; DTwP, diphtheria, tetanus and whole-cell pertussis vaccine; DTaP, diphtheria, tetanus, and acellular pertussis vaccine.
a
Children undervaccinated by 0 doses or 0 days, or none of the dose number of DTwP or DTaP were considered as age-appropriately vaccinated.
b
The ORs and 95% CIs were estimated by conditioning on sex, county of residence, and age at index date.