Fig. 1

Antibody concentrations and percentage of persons with protective antibody concentrations. Diphtheria-specific antibody concentrations were measured by ELISA prior to and 4 weeks after vaccination. Two doses of diphtheria toxoid containing vaccines were applied in a 5-year interval. a Boxes show 25th and 75th percentiles, the median value is indicated. Whiskers depict 5th and 95th percentiles. Only donors, for whom data points were available at all 4 time points are included in the analysis. Differences between CMV-negative and CMV-positive groups were calculated using Mann-Whitney U test. Differences between day 0 (1st vaccination) and day 0 (2nd vaccination) were calculated using Wilcoxon signed-rank test. *p < 0.05; **p < 0.01; n.s.: not significant. b Percentage of participants with antibody concentrations above (protected, solid bar) or below (unprotected, dashed bar) levels considered to be protective (0.1 IU/ml). The CMV-negative group is shown in white, the CMV-positive group in gray. Differences in the percentage of persons protected / unprotected were calculated using Pearson Chi-square test. *p < 0.05; **p < 0.01; n.s.: not significant