Observation on Safety and Immunogenicity of Freeze-dried Live Attenuated Hepatitis A Vaccine

Objective To evaluate the safety and immunogenicity of domestic lyophilized live attenuated hepatitis A(HA) vaccine. Methods Some healthy children at 18～24 months of age were selected to inoculate with a single dose of freeze-dried live attenuated HA vaccine,and the adverse reactions after inoculation were monitored and recorded using a uniform vaccination diary card.The serum samples were collected 28 days poat-vaccination for detection of IgG anti-HAV. Results A total of 354 healthy children aged 18 to 24 months were inoculated with freeze-dried live attenuated HA vaccine.The incidence rates of adverse reactions and febrile response within 14 days were 10.73% and 7.06%,respectively.No severe abnormal responses were observed.333 serum samples were detected effectively.28 days after vaccination,the positive rate of anti-HAV was 92.79% and GMT of anti-HAV was 14.60 mIU/ml. Conclusions Domestic freeze-dried live attenuated HA vaccine shows a good safety and immunogenicity profile.