Proportion of subjects with an SBA titer ≥ 4 against serogroup B (top) and proportion of subjects with an SBA titer ≥ 8 against serogroup C (bottom). Subjects in the MenB/C group received one dose of MenB/C at week 0 followed by two doses of MenBvac (one at week 6 and one at week 12). Subjects in the MenB group received three doses of MenBvac (at weeks 0, 6, and 12). Subjects in the MenC group received one dose of Menjugate at week 0 and placebo (aluminum hydroxide) at weeks 6 and 12. At weeks 0 and 6, serum samples were available from 32 subjects in the MenB/C group, 15 subjects in the MenB group, and 19 subjects in the MenC group. At week 12 the corresponding figures were 30, 15, and 19, and at week 18 they were 29, 14, and 19, respectively. At week 52 the corresponding figures were 27, 15, and 17, respectively.