Persistent and transient hepatitis B virus (HBV) infections in children born to HBV‐infected mothers despite active and passive vaccination

Summary. Combined passive and active immunization for newborns very effectively prevents perinatal hepatitis B virus (HBV) infections. In the Netherlands, babies born to hepatitis B surface antigen (HBsAg)‐positive women receive passive immunization with hepatitis B and at least three active HBsAg vaccinations. Serological testing for the presence of HBV markers was offered for all infants born to HBsAg‐positive mothers between January 2003 and July 2007, after completion of their vaccination schedule. About 75% of the infants (n = 1743) completed their HB‐vaccination schedule and participated in the serologic evaluation. Twelve of them (0.7%) were found to be HBV infected. Furthermore, we identified three older children with high levels of anti‐HBc, anti‐HBs and anti‐HBe, while they were HBsAg and HBV DNA negative. This serologic profile is evidence for a resolved HBV infection. In the group of older children (1.5–5 years of age, n = 728), about half of the HBV‐infected children (3 of 7) had already cleared their infection at the time of sampling. For a proper evaluation of the efficacy of a new intervention programme to prevent vertical HBV transmission, it is also important to analyse the HBV markers in serum collected when the children are older than 1.5 years. In a programmatic setting, all children born to HBV‐infected mothers should be tested not only for the level of anti‐HBs but also for the absence of HBsAg, because 2 of the 12 HBV‐infected children (17%) had a high level of anti‐HBs.