OBJECTIVETo investigate the association of heptitis B virus (HBV) genotypes and precore(PreC)/basal core promoter(BCP) mutation with interruption failure of HBV vaccination in mother-to-infant transmission.

METHODSA total number of 208 serum samples were collected from infants and mothers,including 16 infants who had become HBsAg-positive despite a complete and timely course of immunization and another 88 infants successfully protected from mother-to infant HBV transmission. HBV genotypes were determined by type-specific primers PCR method. PreC/BCP mutations were detected by direct sequencing of PCR products, and Clustal W 1.8 software was applied to analyzing the sequences.

RESULTSOf 16 mothers who were having vaccine failure infants, 15 (93.8%) were HBeAg positive and infected with genotype C (15/15, 100%). Among 88 mothers of having children being protected by vaccine, 51 (58.0%) were HBeAg positive, with 45.1% (23/51) of genotype C. The proportion of genotype C in HBeAg mothers of infants with vaccine failure, was significantly higher than that of mothers with vaccine protected infants (chi2 = 14.3, P = 0.003). However, the frequencies of T1762/A1764 mutations had no significant differences between genotype C HBeAg positive mothers with vaccine failure or protected infants (33.3% and 13.3%, respectively, P = 0.4). No A1896 mutation was found in these two groups.

CONCLUSIONHBV genotype C might contribute to the immune failure of HBV vaccination in mother-to-infant transmission, while PreC/BCP mutation might not have correlation with it.