Table 3. Mean age of carriage of specific serotypes in the pre-vaccine and high-vaccine period.
| Mean age ± standard deviation (yrs) | |||
|---|---|---|---|
| Serotype | Pre-vaccine | High-vaccine | P |
| 6B | 2.8 ± 1.5 | 4.2 ± 1.3 | 0.006 |
| 14 | 2.6 ± 1.5 | 3.5 ± 1.6 | 0.102 |
| 19F | 3.0 ± 1.7 | 3.7 ± 1.5 | 0.004 |
| 23F | 2.9 ± 1.7 | 3.9 ± 1.1 | <0.001 |
| 3 | 4.4 ± 1.0 | 3.9 ± 1.0 | 0.005 |
| 6A | 3.3 ± 1.6 | 3.5 ± 1.4 | 0.093 |
| 19A | 2.9 ± 1.9 | 2.9 ± 1.6 | 0.918 |
| 6C | 3.3 ± 1.7 | 2.8 ± 1.5 | 0.031 |
| 11A | 4.1 ± 1.3 | 3.4 ± 1.8 | 0.012 |
| 15A | 3.0 ± 1.5 | 2.6 ± 1.5 | 0.036 |
| 15B/C | 3.7 ± 1.4 | 3.6 ± 1.6 | 0.491 |
| NT | 2.8 ± 1.6 | 3.3 ± 1.4 | 0.301 |
The trend in the mean age of carriage, for each serotype, was estimated from a generalized linear model in which age was a dependent variable and the vaccine period the independent variable.