Evaluation of the impact of hepatitis B vaccination among children born during 1992-2005 in China

Background. Endemic hepatitis B virus (HBV) infection is a serious health problem in China. Hepatitis B vaccination of infants was introduced in 1992 and was progressively expanded during the subsequent 15 years. Methods. We conducted a national serosurvey, with participants selected by multiple-stage random sampling. Demographic characteristics and hepatitis B vaccination history were collected by a questionnaire and a review of vaccination records, and serum specimens were tested for hepatitis B surface antigen, antibody to hepatitis B core antigen, and hepatitis B surface antibody by enzyme-linked immunosorbent assay. Results. Hepatitis B vaccine coverage (3 doses) increased from 30.0% for children born in 1992 to 93.4% for children born in 2005. Receipt of a timely birth dose increased from 22.2% to 82.6% for children born during this interval. Multivariate analysis showed that older age, western and rural residence, birth at home, and certain ethnicities were risk factors for undervaccination with both full vaccine series and timely birth dose. The prevalence of hepatitis B surface antigen was reduced to 2.1% among all children and 1.0% among children born after 1999. The efficacy of hepatitis B vaccination with a timely birth dose was 88.3%. Conclusions. Hepatitis B vaccine has been successfully integrated into routine infant immunization in China, now reaching most infants within 24 h after birth, and the prevalence of hepatitis B surface antigen has been greatly reduced among children born after 1992.