 The study found that Beijing's reported incidence rate of hepatitis A decreased from 59.41, 100,000 in 1990 to 0.80, 100,000 in 2017, and the average age of infection was postponed from individuals under 20 years old to over 20 years old. The hepatitis A vaccine introduced in Beijing decreased the outbreak of hepatitis sharply. The adjusted anti-HAV positive rate in general population increased from 68.23% in 1992 to 82.47% in 2014, and the coverage rate in target population was higher than 99% after hepatitis A vaccine was integrated into expanded program on immunization, EPI. However, a higher proportion of adults may be susceptible to hepatitis A virus due to the decay of antibodies as they grow up from childhood to adulthood, which may result in possible outbreak of hepatitis A. This article was authored by Huaiwang, Pei Jiayou, Wei Xunchen, and others. We are article.tv, links in the description below.