Assessment on Booster Immunization in Healthy Children with Inactivated Hepatitis A Vaccine and Hepatitis A and Hepatitis B Combined Vaccine

[Objective]To assess the effectiveness and safety of the booster immunization with inactivated hepatitis A vaccine/hepatitis A and hepatitis B combined vaccine,in order to provide the basis for hepatitis A vaccine and hepatitis B vaccine immunization strategy.[Methods]A total of 210 children aged 24-38 months old were divided into two groups.One group were vaccinated with inactivated hepatitis A vaccine and another group waere vaccinated with hepatitis A and hepatitis B combined vaccine.Serum samples were collected after one month and detected anti-HAs with ELISA,anti-HBs with CMIA in order to evaluate GMC and antibody positive rate before and after immunization.Body temperature and clinical symptom were observed for 3 three days in order to evaluate its safety.[Results]Hepatitis A antibody positive rate rose from 95.20% to 100.00% and GMC increased 55.74 times in Hepatitis A vaccine group.Hepatitis A antibody positive rate rose from 88.80% to 98.90% and GMC increased 58.35 times in another group.Hepatitis B antibody positive rate rose from 72.90% to 97.80% and GMC increased from 22.20 mIU/ ml to 1 226.10 mIU/ml which increased by 54.50 times.The effectiveness of booster immunization was very obvious.12 cases were observed with adverse reactions and all were fever.The incidence was 5.74%.Severe adverse reaction was not found.[Conclusion]Inactivated hepatitis A vaccine and hepatitis A and hepatitis B combined vaccine have good immunogenicity and safety.It is recommended to increase a booster immunity to enhance long-term antibody protection.