Table 3.
Subgroup comparison of protective efficacy of typhoid conjugate vaccine
| Typhoid conjugate vaccine group (n=10 005) | Incidence per 100 000 person-years*(95% CI) | Group A meningococcal vaccine group (n=10 014) | Incidence per 100 000 person-years (95% CI) | Vaccine efficacy (95% CI) | p value (interaction) | ||
|---|---|---|---|---|---|---|---|
| Age, years | .. | .. | .. | .. | .. | 0·13† | |
| <2 | 2 | 167 (20– 604) | 0 | .. | .. | .. | |
| 2 to <5 | 5 | 127 (41–296) | 14 | 362 (198–607) | 64·9% (2·5–87·3) | .. | |
| ≥5 | 6 | 46 (17–100) | 47 | 369 (272–489) | 87·5% (70·8–94·5%) | .. | |
| Sex | .. | .. | .. | .. | .. | 0·12 | |
| Male | 5 | 54 (18–126) | 39 | 417 (297–570) | 87·0% (67·1–94·9) | .. | |
| Female | 8 | 90 (39–180) | 23 | 262 (166–392) | 65·6% (23·1–84·6) | .. | |
| Time since vaccination, months | .. | .. | .. | .. | .. | 0·43 | |
| ≤12 | 6 | 61 (23–134) | 36 | 370 (259–512) | 83·4% (60·5–93·0) | .. | |
| >12 | 7 | 83 (34–172) | 26 | 310 (202–454) | 73·0% (37·9– 88·3%) | .. | |
Data are n (%) unless stated otherwise.
*
Blood culture confirmed typhoid fever after 14 days.
†
p value for interaction inclusive of 2 to <5 years and 5 years and older.