Abstract: Objective To evaluate the long term effect of Hepatitis B vaccination by analyzing the serum biomarkers among 0-17 year old children and young adults,so as to determine the necessity of booster vaccination. Method Quantitative analyses of serum HBsAg and HBsAb were performed in 42 905 children and young adults in the hospital.Results Thirty seven（0.087%） children and young adults showed positive HBsAg and 71.33% of them demonstrated positive HBsAb,with 93.41% in 1~2 year old babies but gradual decrease with age. The percentage of the subjects with the concentration of HBsAb over 100 mIU/mL increased from 34.21% in one-month old babies to 88.05% in 7-month ones. Nearly 80% of the subjects from the ages of 4~6 years to 18 years presented the stable level of HBsAg. Conclusion sThe prevalence of hepatitis B virus infection in children and young adults in Anhui is low.Serum HBsAg retest is helpful for evaluating the necessity of HB booster vaccination in preschool children and young adults.

Key words: Hepatitis B virus, Children, HBV Vaccination