Assessment on Effects of Live-attenuated Hepatitis A Vaccine (H_2 strain)

Objective To assess the effects of domestic live-attenuated hepatitis A vaccine in an epidemic.Methods A case-control study of live-attenuated hepatitis A vaccine was conducted in a village with an epidemic of HA.All vaccination histories were obtained from pre-existing immunization records.The effect was estimated.All subjects from 13 primary schools with high morbidity were bled to study the effect on preventing HAV.Results The protective rate of the vaccine was 98.1%,the 95% low confidence interval is 83.5%.The subclinic infection rate of vaccined group and unvaccined group were 10.23% and 11.59% respectively.There had no statistical difference between two groups.Conclusion Domestic live-attenuated hepatitis A vaccine had good protective function.The effects were equal to foreign inactivated vaccine.But the effect to prevent HAV infection was not good.