Table 3.
Estimates of 13-Valent Pneumococcal Conjugate Vaccine Effectiveness Against Colonization in Cambodian Children Aged <5 Years
| Colonization Prevalence (95% CI) | Crude Prevalence Ratio (95% CI) | Adjusteda Prevalence Ratio (95% CI) | P Value | |
|---|---|---|---|---|
| All pneumococci | ||||
| Pre-PCV (2014)b | 68.0 (64.4–71.4) | … | … | … |
| Post-PCV (2016–2018) | 64.2 (61.5–66.7) | 0.944 (.866–1.008) | 0.834 (.782–.894) | <.0001 |
| Early post-PCV (2016–2017) | 62.1 (58.9–65.3) | 0.914 (.851–.982) | 0.806 (.750–.869) | <.0001 |
| Late post-PCV (2018) | 68.2 (63.7–72.5) | 1.004 (.925–1.087) | 0.890 (.820–.966) | .006 |
| VT pneumococci | ||||
| Pre-PCV (2014) | 47.6 (43.9–51.3) | … | … | … |
| Post-PCV (2016–2018) | 32.3 (29.8–34.8) | 0.678 (.609–.757) | 0.608 (.539–.689) | <.0001 |
| Early post-PCV (2016–2017) | 34.1 (31.0–37.3) | 0.716 (.636–.806) | 0.642 (.563–.733) | <.0001 |
| Late post-PCV (2018) | 28.7 (24.6–33.1) | 0.603 (.510–.708) | 0.543 (.455–.644) | <.0001 |
| NVT pneumococci | ||||
| Pre-PCV (2014) | 19.6 (16.7–22.6) | … | … | … |
| Post-PCV (2016–2018) | 31.5 (29.1–34.1) | 1.612 (1.369–1.914) | 1.233 (1.026–1.501) | .03 |
| Early post-PCV (2016–2017) | 27.1 (24.2–30.1) | 1.384 (1.155–1.666) | 1.056 (.865–1.302) | .6 |
| Late post-PCV (2018) | 40.4 (35.8–45.1) | 2.066 (1.718–2.492) | 1.587 (1.297–1.961) | <.0001 |
| NT pneumococci | ||||
| Pre-PCV (2014) | 4.9 (3.4–6.7) | … | … | … |
| Post-PCV (2016–2018) | 4.1 (3.1–5.3) | 0.839 (.557–1.280) | 0.970 (.577–1.731) | .9 |
| Early post-PCV (2016–2017) | 3.5 (2.4–4.9) | 0.711 (.441–1.142) | 0.819 (.460–1.517) | .5 |
| Late post-PCV (2018) | 5.3 (3.4–7.8) | 1.091 (.650–1.800) | 1.275 (.693–2.4414) | .4 |
| Penicillin-NS pneumococci | ||||
| Pre-PCV (2014) | 57.3 (53.6–60.9) | … | … | … |
| Post-PCV (2016–2018) | 50.7 (48.0–53.4) | 0.885 (.816–.961) | 0.775 (.710–.850) | <.0001 |
| Early post-PCV (2016–2017) | 51.8 (48.5–55.1) | 0.904 (.827–.989) | 0.791 (.719–.872) | <.0001 |
| Late post-PCV (2018) | 48.6 (43.9–53.3) | 0.848 (.755–.948) | 0.744 (.660–.838) | <.0001 |
| MDR pneumococci | ||||
| Pre-PCV (2014) | 51.0 (47.3–54.7) | … | … | … |
| Post-PCV (2016–2018) | 44.3 (41.7–47.0) | 0.867 (.792–.954) | 0.740 (.670–.823) | <.0001 |
| Early post-PCV (2016–2017) | 44.1 (40.8–47.4) | 0.864 (.780–.958) | 0.735 (.659–.823) | <.0001 |
| Late post-PCV (2018) | 44.8 (40.2–49.5) | 0.878 (.773–.993) | 0.751 (.658–.856) | <.0001 |
Abbreviations: CI, confidence interval; MDR, multidrug resistant; NS, nonsusceptible; NT, nontypeable; NVT, nonvaccine type; PCV, pneumococcal conjugate vaccine; VT, vaccine type.
aAdjusting for the presence of upper respiratory tract infection symptoms, cohabitation with a child <5 years, definite recent antibiotic use, and enrollment season (January vs August).
bPre-PCV data consist of 2 colonization surveys from January and August 2014.