Abstract: Objective The aim of this study was to investigate immunological response of infants born to hepatitis B viral infected mothers to hepatitis B vaccination and its influencing factors. Methods 86 HBV-infected pregnant women and their 86 infants were encountered in our hospital between January 2019 and December 2020, and out of the 86 hepatitis B viral carriers, 64 women received oral tenofovir at 28 gestational week for blocking hepatitis B viral mother-to-infant transmission until delivering. All infants received hepatitis B immunoglobulin and hepatitis B vaccine routinely, and were followed-up for three years. Serum HBsAg and anti-hepatitis B surface antigen antibody (HBsAb) were detected by ELIS, and serum HBV DNA loads was assayed by PCR. Results By delivery, serum HBV DNA loads transferred to negative in tenofovir-treated women, and by end of three-year follow-up, serum HBsAb positive in 82 infants(95.3%), including weak positive in 16 cases (19.5%) and strong positive in 66 cases (80.5%), and negative in 4 infants (4.7%) in the 86 infants; concomitant diabetes percentage in mother with their infants positive response was much lower than in those with weak response (12.1% vs. 31.2%), while birth weights and gestational weeks were significantly heavier than(3442.7±333.1 g vs. 3385.4±370.6 g)or longer than(39.3±1.2 w vs. 37.4±1.2 w) in weak responders (P<0.05); multivariate Logistic regression analysis showed that concomitant diabetes, low infant birth weight and short gestational weeks at birth were all the risk factors impacting immunological response (P<0.05). Conclusion Hepatitis B vaccination might fails in infants who have a hepatitis B viral infection mothers, the surveillance is important and should re-vaccinates sometimes.

Key words: Hepatitis B viral carriers, Hepatitis B vaccine, Vaccination, Pregnant women, Infants