Maternal anti-HBVs suppress the immune response of infants to hepatitis B vaccine.

It is still controversial whether maternal anti-HBV antibodies (anti-HBVs) affect the infants' immune response to hepatitis B virus (HBV) vaccination. This multicentre study aims to address this question. First, we determined whether the transplacental transfer of maternal anti-HBVs occurs by measuring the titres of 90 anti-HBVs-positive pregnant women and their newborns. The anti-HBVs-positive rates of newborns ranged from 89.7% to 100.0%, depending on the maternal anti-HBVs titres. Secondly, we investigated the effects of maternal anti-HBVs on the immune response of infants to HBV vaccination. A total of 1063 mother-and-infant pairs were enrolled and divided into three groups with maternal anti-HBVs titres of <10 IU/L (negative - 37.9%), 10-499 and ≥500 IU/L. The infants' anti-HBVs-positive rate and titres were negatively correlated with maternal anti-HBVs titres: the anti-HBVs-positive rate of infants were 88.9% (360/405), 84.5% (381/451) and 77.3% (160/207) in mothers with low, intermediate and high antibody titres, respectively, P<.0001. Median titres of anti-HBVs (IU/L) among infants were 169.1, 141.0 and 79.4, respectively, P=.020. One hundred and sixty-two infants were negative for anti-HBVs after the standard vaccination, and 120 of 131 of these infants (91.6%) reached anti-HBVs positivity after the first "booster" dose. The maternal anti-HBVs titres did not significantly affect infant response to this booster. In summary, transplacental transfer of anti-HBVs occurs and high titres of maternal anti-HBVs may suppress the immune response of infants to the standard HBV vaccination. The current schedule of the 0, 1 and 6 month may not be the optimal choice of infants with anti-HBVs-positive mothers.