Table 2.
Baseline demographics of participating women and infants
| Characteristic | Maternal TdaP3-IPV (n = 77) | Maternal TdaP5-IPV (n = 77) | Unvaccinated mothers (n = 25) | Unvaccinated mothers from Infanrix hexa study (n = 18) |
| Women | ||||
| Age, years, median (range) | 34 (20–42) | 32 (21–44) | 31 (20–47) | |
| Ethnicity, n (%) | ||||
| White | 63 (82%) | 63 (82%) | 17 (68%) | 16 (89%) |
| Asian | 6 (8%) | 7 (9%) | 2 (8%) | 1 (6%) |
| Black | 3 (4%) | 3 (4%) | 5 (20%) | 0 |
| Chinese | 1 (1%) | 1 (1%) | 0 | 0 |
| Mixed | 3 (4%) | 3 (4%) | 1 (4%) | 1 (6%) |
| Others | 1 (1%) | 0 | 0 | 0 |
| Site, n (%) | ||||
| Gloucestershire, UK | 3 (4%) | 5 (6%) | 0 | 5 (28%) |
| Hertfordshire, UK | 33 (43%) | 28 (36%) | 3 (12%) | 3 (17%) |
| South London, UK | 41 (53%) | 44 (57%) | 22 (88%) | 10 (56%) |
| Median gestation at vaccination, week (range) | 29 (28–34) | 29 (28–33) | ||
| Median interval from antenatal vaccination to delivery, weeks (range) | 10 (1–14) | 10 (3–14) | ||
| Median interval from delivery to blood sample post-delivery, days (range) [number of samples] | 3 (0–10) [51] | 2 (0–9) [57] | ||
| Maternal TdaP3-IPV (n = 70) | Maternal TdaP5-IPV (n = 74) | Unvaccinated mothers (n = 27) | Unvaccinated mothers from Infanrix hexa study (n = 19) | |
| Infants | ||||
| Twin, n (%) | 6 (9%) | 4 (5%) | 4 (15%) | 2 (11%) |
| Female, n (%) | 33 (42%) | 38 (51%) | 13 (48%) | 10 (52%) |
| Median gestation at birth, weeks (range) | 39 (31–42) | 40 (33–42) | 38.5 (34–42) | 39 (37–42) |
| Median birth weight, kg (range) | 3.39 (1.54–4.69) | 3.52 (1.72–4.93) | 3.42 (2.74–4.20) | |
| Cord blood collected, n (%) | 20 (29%) | 21 (28%) | ||
| Infant peripheral blood collected, n (%) | 37 (53%) | 32 (43%) | ||
| Median interval from birth to 1st infant blood sample, days (range) [number of samples] | 3 (0–10) [57] | 2 (0–9) [53] | ||
| Median age at pre-vaccination blood sample and vaccine dose 1, days (range) [number of samples] | 60 (53–87) [62] | 62 (50–80) [70] | 64 (54–83) [27] | 58 (54–81) [19] |
| Median age at vaccine dose 2, days (range) [number of samples] | 89 (81–113) [63] | 91 (81–108) [69] | 93 (82–125) [27] | 89 (82–121) [19] |
| Median age at vaccine dose 3, days (range) [number of samples] | 120 (108–154) [63] | 116.5 (110–143) [68] | 123 (110–154) [27] | 122 (112–156) [19] |
| Median interval to blood sample after vaccine dose 3, days (range) [number of samples] | 28 (21–47) [62] | 28 (21–55) [65] | 28 (21–52) [27] | 28 (21–40) [18] |
| Median age at “1 year” vaccination, days (range) [n vaccinated] | 372 (351–404) [61] | 372 (358–413) [65] | 373 (366–394) [27] | 377 (354–395) [17] |
| Median interval from “1 year” vaccination to blood sample, days (range) [number of samples] | 28 (21–48) [61] | 29 (21–42) [63] | 29 (21–52) [27] | 31 (21–51) [17] |
Abbreviations: TdaP3-IPV low dose diphtheria, tetanus, acellular pertussis (three pertussis antigens), inactivated poliovirus, TdaP5-IPV low dose diphtheria, tetanus, acellular pertussis (five pertussis antigens), inactivated poliovirus, UK United Kingdom
The following cells are empty as data was not collected from the women recruited in the postnatal period who had not received a pertussis-containing vaccine in pregnancy: maternal age (Infanrix hexa group only), gestation at vaccination, median interval from antenatal vaccination to delivery, median interval from delivery to blood sample post-delivery, birth weight, number of cord blood samples or peripheral blood at birth collected, and median interval from birth to 1st infant blood sample