Impact of hepatitis B vaccination among children in Guangdong Province, China.

To evaluate the impact of the universal infant hepatitis B vaccination program on hepatitis B virus (HBV) infection in Guangdong Province, China.In 2006, a serosurvey was conducted in Guangdong Province among children aged <15 years, 14 years after the introduction of universal infant hepatitis B vaccination. The participants were selected by stratified, multi-stage random sampling. Demographic characteristics and hepatitis B vaccination history were collected by a questionnaire and a review of the vaccination records, and serum specimens were tested for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc), and antibody to hepatitis B surface antigen (anti-HBs) by ELISA. The prevalence rate of HBV serological markers and the rate of immunization coverage in this survey were compared with those of the 1992 and 2002 surveys.A total of 1967 children aged <15 years participated in 2006. The prevalence rate of HBsAg decreased from 19.86% in the 1992 survey to 4.91% in the 2006 survey. The rates of three-dose and timely birth dose coverage of hepatitis B vaccine were 92.40% and 70.84%, respectively, among children born during the period 2002-2005. The prevalence of HBsAg was significantly lower among fully immunized children (1.99%) than among unvaccinated children (5.56%).Guangdong Province has successfully integrated the hepatitis B vaccine into routine immunization programs and this has had a very significant impact on decreasing the HBsAg carrier rate among children.