Study on the Safety and Immunogenicity of China Made Inactivated Hepatitis A Vaccine in HAV Susceptive Children

Objective To investigate the safety and immunogenicity of a domestic inactivated hepatitis A vaccine when applied to young children (1-4 years old) .Methods sixty - three susceptible healthy children whose age range from 1 to 4 were divided into two groups at random, and inoculated with 500u/dose according to the 0, 3 months schedule or 0, 6 months schedule.The local and the systemic side effects were observed after vaccination, the seroconversion rate and geometric mean tilers (GMT) of hepatitis A virus antibodies were evaluated after primary immunization and the booster as well. Results The local and systemic effects reactions after the primary immunization and the booster immunization are slight and temporary. Abnormal liver .function was not observed. The seroconversion rates of HAV antibody were 85.7%, 88.5% and 83.8% corresponding to the 1, 3, 6 months after the primary immunization, and its GMTs were 182mIU/ml, 243mIU/ml, 280mIU/ml res pectively.Both seroconversion rate for0, 3 months schedule and 0, 6 momths schedule were 100% 1 month after booster, while the anti - HAV GMTs for which were 2718mIU/ml and 4683mIU/ml respectively. Conclusion The domestic inactivated hepatitis A vaccine has satisfactory safety and immunogenicity when applied to young children; 0, 6 months schedule was better than 0, 3 months schedule.