A comparative efficacy trial of different schedules of immunization with a recombinanat yeast derived hepatitis B vaccine

In order to evaluate the safety and immunogenicity of 0、1、2 and 0、1、6 schedules with a recombinanat yeast derived hepattitis B vaccine(YDV),two batches of YDV produced by National Vaccine and Serum Institute Products(5ug/dose)were administered to 393 school children.No serious side effects were found.At the third month after the first dose(T3),the anti-HBs positive rates of all groups were above 88% and reached the peak at the seventh month(T7),and declineds lowly afterwards.The GMT of 0、1、2 schedule in both batches were significantly higher than at T3,but much lower at T7,as compared with 0、1、6 schedule.