Hepatitis B Vaccination and Factors Related with Unresponsiveness in Healthy Children

Abstract

Background: The aim of this study was to assess the effectiveness of HBV vaccination and factors associated with vaccine unresponsiveness in healthy children. Methods: A total of 141 healthy children aged between 2-5 years were included in the study. All of the cases had received 20 µg of recombinant DNA vaccine for hepatitis B (0,1 and 6 months). Demographic features and the factors such as duration of breastfeeding, exposure to HBsAg-positive family members, administration of concomitant vaccines and exposure to smoke were determined. HBV serological markers were evaluated. Postvaccination serologic evaluation was performed one month after the last dose of primary vaccination, one month after the booster dose. HLA typing was performed in nonresponders. Results: 87.9% of the children achieved seroprotection (anti-HBs titres ≥10 mIU/ml) one month after primary vaccination. No difference was observed between vaccine responsiveness and age, sex, birth weight, maturity, duration of breastfeeding, exposure to HBsAg-positive family members and mid-upper arm circumference (P>0.05). A significant correlation was obtained between anti-HBsAg titers and midupper arm circumference (P=0.005). HLA types, DRB 111 (64.7%), B5 (52.9%), DRB 104 (52.9%) and DRB 11001 (47%) were detected at increased frequency in nonresponders. Conlusions: The antibody titers were significantly higher in children who breastfed for the first 6 months and longer and who were vaccinated concomitantly with other common vaccines.