Table 3.
Anti-PPS specific IgG isotype levels in young and elderly.
| Pre-immune, GMC (95% CI) | Post-immune GMC (95% CI) | P value | ||
| IgG1 | ||||
| PPS4 | Young | 0.13 (0.06) | 0.35 (0.18) | 0.001 |
| Elderly | 0.14 (0.09) | 0.33 (0.38) | 0.051 | |
| PPS14 | Young | 0.87 (0.13) | 3.59 (0.33) | 0.001 |
| Elderly | 0.93 (0.44) | 1.19 (0.95) | 0.015 | |
| IgG2 | ||||
| PPS4 | Young | 1.03 (0.37–1.69) | 5.14 (0.64–9.64) | 0.010 |
| Elderly | 0.83 (0.04–1.62) | 1.96 (0.98–2.94) | 0.005 | |
| PPS14 | Young | 2.18 (1.86–2.50) | 12.33 (4.51–20.15) | 0.002 |
| Elderly | 1.36 (0.62–2.10) | 4.78 (2.37–7.19) | 0.004 | |
Geometric mean concentration (GMC μg/ml) of anti-PPS antibody in pre-and post-immunization serum from young and elderly volunteers measured following absorption with CPS. P values shown in bold indicate significant difference between pre and post immunization by two tailed paired students T-test