TABLE 3

Effect of age on pneumococcal OPA GMTs in the evaluable immunogenicity populationa

SerotypeOPA GMTs atb:
PrevaccinationPostvaccination
50–64 yr (n = 142–159)≥65 yr (n = 146–161)Comparisonc50–64 yr (n = 148–155)≥65 yr (n = 150–159)Comparisonc
Ratio95% CIRatio95% CI
1670.80.64, 1.00120841.40.96, 2.10
37110.60.48, 0.8688891.00.74, 1.33
430530.60.32, 1.061,7291,2091.41.05, 1.95
57100.70.51, 0.992882851.00.65, 1.58
6A571100.50.30, 0.913,3803,3431.00.73, 1.39
6B2353880.60.33, 1.103,9823,3841.20.88, 1.58
7F661250.50.29, 0.983,1301,9291.61.25, 2.11
9V2641731.50.81, 2.882,4161,4021.71.17, 2.54
142913610.80.50, 1.301,5691,3161.20.89, 1.60
18C701550.40.24, 0.833,0632,1971.40.99, 1.96
19A521050.50.32, 0.771,5421,1961.30.98, 1.70
19F26530.50.29, 0.8511041,1880.90.63, 1.38
23F13250.50.34, 0.828799300.90.60, 1.48
  • a OPA, opsonophagocytic activity; GMT, geometric mean titer.

  • b n values are the numbers of subjects with a valid and determinate OPA titer to the given serotype. The GMTs were calculated using all subjects with available data for the specified blood draw.

  • c The ratio of GMTs (50 to 64 years GMT/≥65 years GMT) was calculated by back transforming the mean difference between the age groups on the logarithmic scale. The 95% confidence intervals (CIs) for the ratios are back transformations of a CI based on the Student t distribution for the mean difference of the logarithms of the measures (50 to 64 years data − ≥65 years data). The statistically significant differences are in bold type.