Reduced mother-to-child transmission of hepatitis B after implementation of completely charge-free active-passive immunoprophylaxis: an observational cohort study.

: China has implemented universal hepatitis B vaccination since 2002 and provided charge-free hepatitis B immunoglobulin (HBIG) to infants of HBV-infected mothers since July 2011. We aimed to compare mother-to-child transmission (MTCT) in children born before and since July 2011.: In total, 5,149 children of HBV-infected mothers were tested for HBV markers. Group one contained 1,160 children born during August 2002-June 2011 and group two contained 3,989 children born during July 2011-June 2016.: In total, 92 (1.8%, 95% confidence interval [95%CI] 1.4-2.2) children were infected with HBV. None (0%, 95%CI 0.0-0.1) of 3,716 children of mothers with negative hepatitis B e antigen (HBeAg) was infected, whereas 92 (6.4%, 95%CI 5.2-7.8) of 1,433 children of HBeAg-positive mothers were infected (p < 0.0001). Among children of HBeAg-positive mothers, MTCT occurred in 10.3% (19/185) (95%CI 6.3-15.6) in group one and 5.8% (73/1,248) (95%CI 4.6-7.3) in group two (p = 0.02).: Implementing charge-free active-passive immunoprophylaxis greatly reduces MTCT of HBV in children of HBeAg-positive mothers, highlighting the importance of timely administration of both hepatitis B vaccine and HBIG to prevent MTCT. The still remaining MTCT suggests that reducing maternal virus load before delivery is an additional important measure.