Fig. 1

The recruitment process of mother-infant pairs in the study of outcomes of the national programme on PMTCT of HBV in China, 2016–2017. PMTCT: Prevention of mother-to-child transmission; HBV: Hepatitis B virus; HBsAg: Hepatitis B surface antigen; HBeAg: Hepatitis B e antigen; anti-HBs: Hepatitis B surface antibody; HBvacc: Hepatitis B vaccine; 3-dose HBvacc series: First dose within 24 hours of birth, second dose after 1 month, third dose after 6 months, *Children had HBV serological marker test