Correlation of log ₁₀ MenC-specific plasma cell response with log ₁₀ absolute increase in MenC antibody response. Data points marked by ▴ represent individuals who received MenCC; those with ○, individuals who received MenCPS. Pearson correlation coefficient was 0.58 for the MenCC group (P < .001) and 0.22 for the MenCPS group (P = .27).