Hepatitis B vaccine response among infants born to hepatitis B surface antigen-positive women

Abstract

Purpose: Annually, an estimated 25,000 infants are born to hepatitis B surface antigen (HBsAg)-positive women in the United States. Hepatitis B (HepB) vaccine and hepatitis B immune globulin (HBIG) are recommended at birth, followed by completion of vaccine series and post-vaccination serologic testing (PVST). In a large cohort of infants born to HBsAg-positive women, factors influencing vaccine response were evaluated.

Methods: Data were from HBsAg-negative infants born to HBsAg-positive women in the Enhanced Perinatal Hepatitis B Prevention Program (EPHBPP) from 2008 to 2013. Vaccine non-responders were defined as infants with antibody to hepatitis B surface antigen (anti-HBs) <10mIU/mL at PVST after receiving ≥3 vaccine doses. Multivariable analyses modeled statistically significant predictor variables associated with non-response.

Results: A total of 17,951 maternal-infant pairs were enrolled; 8654 HBsAg-negative infants born to HBsAg-positive mothers received ≥3 doses of vaccine with anti-HBs results. 8199 (94.7%) infants responded to a primary HepB series; 199 (94.8%) to a second series. Factors associated with anti-HBs <10mIU/mL included gestational age <37 weeks, vaccine birth dose >12h after birth, timing of final vaccine dose <6 months after birth, receipt of 3 vs. 4 vaccine doses, and PVST interval >6 months from final vaccine dose in bivariate analysis. PVST interval >6 months from final vaccine dose (OR=2.7, CI=2.0, 3.6) was significantly associated with anti-HBs <10mIU/mL; the proportion increased from 2% at 1-2 months to 21.6% at 15-16 months after the final dose. Receipt of a 4th dose improved the response rate (OR=0.5, CI=0.3, 0.8).

Conclusions: Ninety-five percent of a large cohort of uninfected infants born to HBsAg-positive mothers in the United States responded to primary HepB vaccine series. The proportion of infants with anti-HBs <10mIU/mL increased with longer interval between the final vaccine dose and PVST. Optimal timing of PVST is within 1-2 months of final vaccine dose to avoid unnecessary revaccination.

Keywords: Antibody response; Hepatitis B; Immunization; Perinatal; Vaccine.