Post-vaccination serological test results of infants at risk of perinatal transmission of hepatitis B using an intensified follow-up programme in a London centre.

Immunisation of infants born to hepatitis B virus (HBV) infected mothers is an important public health measure to prevent mother-to-child transmission of HBV. Post-vaccination serological tests (PVST) inform the success of the infant HBV immunisation programme and identify infected infants. Previous studies suggested that the rates of PVST in the UK programme were unsatisfactory. We introduced an intensified local follow-up programme and offered an earlier PVST 2-3 months after the third vaccination at age 4-5 months. Of 219 infants born between 2009 and 2011, 193 infants (88.1%) had at least one PVST: 145 (66.2%) early; 94 (42.9%) standard; 46 (21.0%) both and 26 (11.9%) never tested. Twenty-four infants were identified as high risk for mother-to-child transmission according to national criteria and received both hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine at birth. These infants had a significantly lower hepatitis B surface antibody (anti-HBs) levels at early PVST compared to the lower risk group who received hepatitis B vaccine only (median of 59 vs. 376 mIU/ml, P=0.006). None of the infants tested were infected with hepatitis B. This study illustrates that the rate of PVST can be improved by using an intensified follow-up programme offering an early PVST. The significantly lower anti-HBs levels in the HBIG subgroup is of concern as this group of infants is already at higher risk for acquiring HBV infection. Infants with poor antibody responses can be identified by an early PVST and offered a timely extra booster dose.