A Study of Long-term Efficacy of Hepatitis B Vaccine in Children of HBsAg Positive Mothers

82 infants who were born by HBV carrier mothers were divided into two groups according to randomized,placebo-controlled method,one was vaccine group and another was controlled group(proprotion of number was 3:1). The three doses of hepatitis B vaccine were injected oninfants which were in vaccine group within 24 hours after born,first month and 6th month. It was the same in controlled group but vaccine was replace by placbo. The rate of anti-HBs Positive in vaccine group was the peak(67. 8% 40/ 59)on 12th month,then it come to decline slowly to(59.32 %(35/59)on 13th years. There are 23. 53 %(4/ 17)subjects become anti-HBspositive in controlled group by natural infection. The difference between the groups are significance during the studying time. On the contrary with anti-HBs,the rates of HBsAg Have being lower in vaccine group than controlled group during the time. They were 18.64 % in vaccine group and 47. 06% in controlled group tespectively on 13th year(P<0.05).