Efficacy of emergency vaccination of inactivated hepatitis A vaccine

Objective The study was conducted to detect the hepatitis A virus antibody(Anti-HAV) levels in general population during the hepatitis A epidemic,evaluate the efficacy of emergency vaccination of inactivated Hepatitis A vaccine.Methods Epidemiological survey was conducted among hepatitis A patients and close contacts,anti-HAV level detection was performed in the population,and the emergency vaccination of inactivated hepatitis A vaccine was implemented.3365 students received the vaccination directly in school and 108 close contacts of hepatitis A patients were vaccinated after screening to assess the safety of vaccines,antibody response over time and protective efficacy of emergency vaccination.Results The overall positive rates of anti-HAV in the population reached 77.82% during the epidemic period.The protection rate of the vaccine among the students and close contacts vaccinated reached 100.00%.The proportion of hepatitis A case of ≤20 age group declined from 38.89% before the vaccination to 19.44% two months later after the vaccination,and the positive conversion rate of anti-HAV among the close contacts reached 80.00% four weeks later after the vaccination.Conclusion Inactivated hepatitis A vaccine is safe and quick to produce protective antibodies after emergency vaccination.Therefore,it can be used to control HAV infection during the hepatitis A epidemic.