Antibody response to pneumococcal vaccination as a function of preimmunization titer

Antibody response interpreted as fold increase (postimmunization vs preimmunization) in titer on a per-serotype basis. A, The percentage of subjects per serotype with a preimmunization titer of 1.3 μg/mL or greater. B, Geometric mean fold increase associated with preimmunization titers of 1.3 μg/mL or greater. C, The percentage of subjects with preimmunization titers of 1.3 μg/mL or greater who achieved at least a 4-fold increase over baseline.

Results from multivariable logistic regression analysis of antibody response as a function of preimmunization titer adjusted for age, sex, and IgG level. The data shown represent the odds ratio of a 4-fold or greater increase in antibody titer as a function of the absolute preimmunization titer, starting at the lower limit of 1.3 μg/mL. As the absolute preimmunization titer value increases, the odds ratio of a 4-fold or greater response approaches zero for all serotypes. The solid line represents the mean value, and the dashed lines represent the 95% CIs.

The patients were divided in 2 categories: those who were eventually given a diagnosis of an immune abnormality and those who were not found to have any major immunodeficiency. The latter group was considered normal subjects (n = 223). The values for the normal subject (A) and patient (B) groups were reanalyzed, and the odds ratio was calculated as in Fig 2.