Initial anti-HBs titers of primary responders after full series of vaccination and its duration of positivity.

<p>(A) A box indicates a median and interquartile range, and error bars denote the 10th and 90th percentiles. (B) High (> 500 mIU/mL, n = 35), moderate (100–500 mIU/mL, n = 62), and low (< 100 mIU/mL, n = 46) titers. It was a significant trend that individuals with lower titers of initial anti-HBs experienced secondary vaccine response failure earlier.