TABLE 4

Comparison of pneumococcal OPA GMTs in subjects 50 to 64 years of age in Mexican study versus U.S. comparator study in the evaluable immunogenicity populationsa

SerotypeOPA GMTs atb:
PrevaccinationPostvaccination
Mexican study (n = 142–159)U.S. study (n = 672–795)ComparisoncMexican study (n = 148–155)U.S. study (n = 709–786)Comparisonc
Ratio95% CIRatio95% CI
1651.10.94, 1.241201710.70.53, 0.94
3771.00.84, 1.2488921.00.76, 1.20
430162.01.23, 3.091,7292,4120.70.53, 0.96
5761.31.05, 1.522882311.20.88, 1.78
6A57163.52.35, 5.323,3803,3311.00.75, 1.37
6B235386.13.68, 10.263,9822,5161.61.16, 2.15
7F6679.26.55, 12.823,1301,3012.41.75, 3.30
9V2642411.06.81, 17.862,4161,4161.71.22, 2.38
14291358.25.30, 12.781,5697652.11.45, 2.91
18C70233.01.95, 4.603,0631,8281.71.22, 2.30
19A52252.11.51, 2.851,5428051.91.52, 2.41
19F26171.51.07, 2.211,1045562.01.41, 2.80
23F1381.61.20, 2.148794302.01.38, 3.03
  • 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 (Mexican study to U.S. study) was calculated by back transforming the mean difference between the studies on the logarithmic scale. The 95% confidence intervals (CIs) for the ratio are back transformations of a confidence interval based on the Student t distribution for the mean difference of the logarithms of the measures (Mexican study to U.S. study). The statistically significant differences are in bold type.