Comparison of immune response to hepatitis B vaccine between term and preterm infants at birth

Background: Hepatitis B vaccination of the newborn prevents prenatal transmission of hepatitis B virus. American Academy of Pediatrics (AAP) recommends that preterm infants weighing less than 2000 grams at birth who born to HBS-Ag negative mothers should receive their first dose of hepatitis B vaccine as early as one month of age. The aim of the present study was to assess and compare the immune response of preterm and term infants to hepatitis B vaccine. Materials and methods : Forty-eight preterm and 49 term neonates were enrolled for this case-control study. The vaccine was administered at birth, 1.5 and 9 months of age. Antibodies against hepatitis B surface antigen (Anti–HBS) were measured in all infants at 15 months of age. Results: The study population included 24 boys and 24 girls with the mean birth weight of 1595.7±388.3 g. The mean gestational age of preterm infants was 32.4±2.1 weeks. Immune response to HB vaccine was protective and similar in both preterm and term infants (85.4 vs. 85.7%, NS). There was no significant association between the type of response and the infantʹs birth weight or sex. However, there were significant associations between antibody titer and use of mechanical ventilation and sepsis (p < 0.01 for both). Conclusion: Preterm and term infants have similar and effective response to hepatitis B vaccine when given immediately after birth.