Safety and immunogenicity of a new inactivated hepatitis A vaccine in children and adults

Objective To assess the safety and immunogenicity of a new inactivated hepatitis A vaccine in children and adults. Methods 176 healthy children and 206 healthy adults with both HBsAg and hepatitis A IgG antibody negative selected from Mengshan County of Guangxi Zhuang Autonomous Region were randomly divided into 4 groups. 107 children(group A) and 131 adults(group B) were received 640EIU/ 1.0ml and 1440EIU/1.0ml of home-made inactivated hepatitis A vaccine (Institute of Medical Biology, Chinese Academy of Medical Sciences), 69 children (group C) and 75 adults (group D) were given 720 EIU/ 1. 0ml and1440EIU/ 1.0ml of inactivated hepatitis A vaccine (SmithKline, Beecham Biologicals) by 0, 6 month schedule.The local and systemic side-effects were recorded the first 72 hours after each vaccination. Seroconversion rate and geometric mean titer (GMT) of antibody to hepatitis A were tested at months 1, 6 and 7 after first dose of vaccination. Results Local and systemic side effects were not observed in all participants within 3 days after first dose vaccination and no elevation of ALT was found. One month after first dose of vaccination, the seroconversion rates and GMTs of anti - HAV IgG were 94.8% and 96.7% as well as 758.6mIU/ ml and, 3630.8 mIU/ ml in group A and B , respectively . One month after second dose of vaccination, the seroconversion rates of anti - HAV IgG of all 4 groups were 100% , the GMTs in group A and B ( 10471.2 mIU/ml and 12302.7 mIU/ml )were more higher than those in group C and D(3090.3 mIU/ml and 3388.4 mIU/ml) .Conclusion The home-made new inactivated hepatitis A vaccine was safe and highly immunogenic.