Safety and immunogenicity of a new inactivated hepatitis A vaccine(Vero cell):A randomized control trial

Objective To assess the safety and immunogenicity of a new inactivated hepatitis A vaccine (Vero Cell).Methods 1507 subjects were selected in Gongcheng City of Guangxi Zhuang Autonomous Region, and the clinical trail was carried out according to the random, double-blind and parallel principle from January to August, 2005. After vaccination by 0, 6 schedule, adverse events of the subjects were observed, the seroeonversion rate and geometric mean titer (GMT) were tested by the competitive inhibition ELISA. Results After immunization, the systemic and local reaction rates of adults were 8.80% And 2.67% respectively, which was no significantly statistical difference compared with control group, 12.41% and 4.41% ; while the rates of children were 10.60 and 2.28% respectively, and no significant statistical difference compared with control group, 10.71% and 2.86% . One month after first dose of vaccination, the seroconversion rates of children and adults were 88.2% and 93.8% , and one month after second dose of vaccination, the rates all reached 100% , the GMTs of children and adults were 16447 mIU/m1 and 8555 mIU/ml, which was significant statistical difference in children compared with control group, 1946 mIU/ml and 5881 mIU/ml, respectively. Conclusion The new inactivated hepatitis A vaccine(Vero Cell) has the same result in safety compared with the imported vaccine, and the seroconversion rates was 100% by 0, 6 schedule, with highly antibody titer.