Clarification to Long-term anti-HBs antibody persistence and immune memory in children and adolescents who received routine childhood hepatitis B vaccination. Hum Vaccin Immunother 2012; 8:813-8

Abstract

Purpose: This paper presents data from two studies that evaluated 5-year and 10-year persistence of antibodies against hepatitis B (HBV) surface antigen (anti-HBs) and immune response to an HBV vaccine challenge in children and adolescents who had received three doses of a HBV vaccine in infancy as part of routine clinical practice [NCT00519649/ NCT00984139]. Results: Anti-HBs antibody concentrations ³ 10mIU/ml persisted in 83.3% (95% confidence interval [CI]: 78.5−87.5) and 78.3% (95% CI: 73.1−83.0) of subjects aged 7−8 years and 12−13 years, respectively 5−10 years after infant vaccination. One month post-challenge dose, 98.2% (95% CI: 95.9−99.4) and 93.7% (95% CI: 90.2−96.2) of subjects in the two age groups, respectively had anti-HBs antibody concentrations ³ 100mIU/ml. Overall, 99.6% (95% CI: 98−100) and 97.2% (95% CI: 94.5−98.8) of subjects aged 7−8 years and 12−13 years mounted an anamnestic response to the HBV challenge dose, which was well-tolerated. Methods: Healthy children aged 7−8 years and adolescents aged 12−13 years received three doses of a monovalent pediatric HBV vaccine (10µg of HBsAg) before 18 months of age. Serum samples collected before and one month post-HBV vaccine challenge dose were tested for anti-HBs antibody concentrations. Safety assessments were made for the HBV vaccine challenge dose. Conclusions: A three-dose childhood HBV immunization regimen induced persistence of antibodies against HBV infection for 10 years, up to adolescence. This vaccination regimen also conferred long-term immune memory against HBV as evidenced by the strong anamnestic response to the HBV vaccine challenge, despite waning anti-HBs antibody levels.