Should a booster dose be administered in children after mass immunization for hepatitis B?

Background: hepatitis b virus infection is a global health problem and vaccine-preventable disease, but the duration of the effects of hbv vaccination in infants is unknown.objectives: the aim of this trial, which comprised children who had received 3 doses as part of the universal hbv immunization program and no additional doses, was to investigate anti-hbs titers and hbsag status after 9 years.patients and methods: we performed a descriptive, cross-sectional field research study. the study sample, based on sociodemographics and minimum seroprevalence, was analyzed based on 10.00% ± 1.50 (95% confidence interval) (1150 individuals); trial was realized in a total of 1279 children (623 females and 656 males). anti-hbs titers were measured by micro-eia (dia sorin-italy); titers < 10 iu/ml were negative, 10-49 iu/ml were low-positive, and > 50 iu/ml were high-positive. for anti-hbs titers below protective levels, hbsag was measured by micro-eia.results: in approximately half of the children (48.5% in those living in semiurban areas and 42.3% in urban areas), antibody titers were below protective levels.conclusions: mass hbv vaccination, which was implemented in turkey in 1998, significantly decreases hbsag positivity in childhood. nevertheless, it might be necessary to administer a booster dose after 8-9 years in children, especially those in low socioeconomic areas or in whom irregular/insufficient immunization is suspected.