Abstract: Objective To investigate the prevalence of hepatitis B among children in a certain area after the planned immunization with hepatitis B vaccine through seroepidemiological studies. Methods The study were conducted from February 2019 to December 2020. Used the multi-stage stratified random cluster sampling method, 300 cases of children who completed the planned immunization of hepatitis B vaccine in a certain area were selected as the study subjects. The seroepidemiological tests were carried out on all children, and general data of children were investigated and Spearman correlation analysis was carried out. Multivariate analysis of influencing factors of HBV infection was carried out by Logistic regression. Results In the 300 children, serum HBsAg positive was 6.00%, serum anti-HBc 10.67% and serum HBsAb 9.33% . In 6 children of hepatitis B, the prevalence was 2.00%, including 6 men and 0 women. There was no difference in the prevalence of male and female populations (P>0.05). Spearman analysis showed that there were correlation between male, being deliverd in hospital under county level, cesarean section, preterm delivery, father's HBsAg positive, mother's HBsAg positive, delayed vaccination, low birth weight and hepatitis B infected (P<0.05). Logistic regression analysis showed that father's HBsAg positive, delayed vaccination and mother's HBsAg positive were the risk factors for hepatitis B disease in certain area after hepatitis B vaccine immunization (P<0.05). Conclusion The prevalence rate of hepatitis B among children in a certain area after the planned immunization of hepatitis B vaccine is relatively low. The risk factors for the prevalence of hepatitis B are HBsAg positive children guardians and untimely vaccination, and preventive management should be actively strengthened.

Key words: hepatitis B vaccine, planned immunization, a region, children, seroepidemiology, multifactor analysis