A 14 Years Cohort Study on Immune Efficacy of Plasma-derived Hepatitis B Vaccine in Children with 2 Doses Schedule

Objective To understand the protective efficacy of plasma-derived hepatitis B vaccine in two-doses schedule.Methods In 1985,261 HBV susceptible children of 1-7 years old were immunized with plasma-derived hepatitis B vaccine by 0,3 months schedule(10μg,10μg)in Hebei rural area.They were followed up for 14 years.Their serum samples were detected for hepatitis B infection markers,including HBsAg,anti-HBs and anti-HBc by RTA methods.Results The anti-HBs positive rates were 93.57% at the 1st year after vaccination,but gradually decresed to 52.13% at the 14th year.In the period of 14 years follow-up,1 child became HBsAg positive conversion at the 6th year after vaccination.Conclusion This practice showed that the efficacy of two-doses immunization schedule was good as three-doses schedule,which can pro- tect HBV susceptible children for a long time,and was worthy to be popularized in less developed areas.