Table 3.
Sensitivity analyses of lab-confirmed and epi-linked cases, and age-specific vaccine effectiveness. Borno, December 2018 – March, 2019
| Original VE | Sensitivity analyses | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| VE for lab-confirmed cases | VE for epi-linked cases | ||||||||
| Age Group | VE% (95% CI) | Vaccinated cases | Confirmeda cases | PCV (95% CI) | VE% (95% CI) | Vaccinated cases | Confirmeda cases | PCV (95% CI) | VE% (95% CI) |
| < 9 mob | – | 0 | 2 | 0.00 (0.00–0.84) | – | 1 | 47 | 0.02 (0.00–0.11) | – |
| 9–11 mo | 87.3 (71.0–95.2) | 1 | 3 | 0.33 (0.01–0.91) | 68.3 (−509–99.5) | 6 | 39 | 0.15 (0.06–0.31) | 88.5 (72.1–96.1) |
| 12–23 mo | 96.2 (92.6–98.3) | 1 | 12 | 0.08 (0.00–0.38) | 95.9 (71.5–99.9) | 8 | 106 | 0.08 (0.03–0.14) | 96.3 (92.4–98.4) |
| 24–35 mo | 97.3 (95.1–98.7) | 0 | 11 | 0.00 (0.00–0.28) | 100.0 (92.4–100.0) | 12 | 86 | 0.14 (0.07–0.23) | 96.9 (94.3–98.5) |
| 36–47 mo | 98.6 (96.7–99.6) | 0 | 7 | 0.00 (0.00–0.41) | 100.0 (86.8–100.0) | 5 | 68 | 0.07 (0.02–0.16) | 98.5 (96.3–99.5) |
| 48–59 mo | 89.2 (77.9–95.2) | 1 | 8 | 0.13 (0.00–0.51) | 94.0 (53.0–99.9) | 9 | 41 | 0.22 (0.11–0.38) | 88.1 (74.5–95.0) |
| 60–71 mo | 99.5 (98.3–99.9) | 0 | 7 | 0.00 (0.00–0.41) | 100.0 (95.6–100.0) | 3 | 31 | 0.10 (0.02–0.26) | 99.3 (97.8–99.9) |
| Overall | 98.4 (97.8–98.8) | 3 | 50 | 0.06 (0.01–0.17) | 99.1 (97.2–99.8) | 44 | 418 | 0.11 (0.08–0.14) |
98.3 (97.7–98.8) |
Mo month, PCV Proportion of cases vaccinated, PP Proportion of the population vaccinated based on 2018 PCCS report, VE Vaccine effectiveness, CI Confidence Interval
aCases reported from IDP camps were excluded from the VE estimation as the PCCS did not capture coverage from IDP camps
bThe < 9 months’ infants were not scheduled for measles vaccination and were excluded from the VE estimation