Table 3. Geometric Mean Concentrations (GMCs) of Meningococcal Serogroup C Polysaccharide (MenC-PS) Specific Immunoglobulin G (IgG) prior to (T0) and 1 Month (T1) and 1 Year (T2) after the MenC Conjugate Booster.
| Age at T0 | P-value difference between groups* | ||||||
| 10 years | 12 years | 15 years | 10 vs. 12 | 10 vs. 15 | 12 vs. 15 | ||
| T0 | No. analyzed | 91 | 91 | 86 | |||
| GMC MenC-PS specific IgG µg/mL (95%CI) | 0.26 (0.22–0.31) | 0.32 (0.26–0.39) | 0.40 (0.31–0.51) | 0.444 | 0.018 | 0.579 | |
| T1 | No. analyzed | 88 | 90 | 85 | |||
| GMC MenC-PS specific IgG µg/mL (95%CI) | 134 (117.0–153.4) | 193.6 (168.2–222.3) | 174.3 (147.5–206.0) | <0.001 | 0.063 | 1.000 | |
| T2 | No. analyzed | 85 | 89 | 83 | |||
| GMC MenC-PS specific IgG µg/mL (95%CI) | 12.2 (10.2–14.4) | 23.3 (19.3–28.0) | 33.7 (28.4–39.9) | <0.001 | <0.001 | 0.033 | |
| T1/T0 | GMC ratio (95%CI) | 511 (417–627) | 607 (469–787) | 439 (322–598) | 0.924 | 1.000 | 0.345 |
| T1/T2 | GMC ratio (95%CI) | 11.0 (9.5–12.8) | 8.3 (7.1–9.8) | 5.2 (4.5–6.2) | 0.036 | <0.001 | <0.001 |
NOTE: Differences between age groups in GMC of MenC-PS specific IgG were determined with linear regression analyses, adjusting for concentrations at T0. GMC ratios indicate the level of increase (T1/T0) or decrease (T1/T2) between time points. Differences in GMC ratios between groups were determined with independent sample t-tests.
* P-values were adjusted for three comparisons with Bonferroni correction. Extensive results of the crude and adjusted linear regression analyses are outlined in supplementary table S1.