Ex vivo IFN-γ ELISPOT responses to the vaccine insert. Median with individual ex vivo IFN-γ ELISPOT responses from vaccinated volunteers at baseline (week 0), and weeks 1, 3, 8, 12, 24, and 52 weeks after immunization. (A) group 1; (B) group 2; (C) group 3. Wilcoxon signed rank test was used to determine significant differences in the post- and prevaccination time points. (A) week 1, P = .0059; week 3, P = .0098; week 8, P = .0078; week 12, P = .0049. (B) week 1, P = .0313; week 3, P = .0313. (C) week 1, P = .0078; week 3, P = .0078; week 8, P = .0078; week 12, P = .0078; week 24, P = .023. Significant differences were detected between groups 2 (B) and 3 (C) at all postvaccination time points apart from week 52 (Mann-Whitney U test: week 1, P = .006; week 3, P = .04; week 8, P = .01; week 12, P = .02; week 24, P = .012).