Immune Response against Hepatitis B Vaccine in Transfusion-Dependent Thalassemic Children Vaccinated in Early Infancy

Abstract

Background and Objectives: Children with thalassemia are much more vulnerable to being infected by hepatitis B virus (HBV) through transfusion of blood and blood products. Although active immunization against HBV in early infancy is being conducted in Bangladesh by the inclusion of the hepatitis B vaccine (HepB) in the expanded programme on immunization schedule, these children might have altered immune response against HepB due to inevitable iron overload resulting from the disease thalassemia itself as well as repeated transfusion therapy and also from exposure to different allogeneic antigens. The present study was designed to determine the immune response of HepB among transfusion-dependent thalassemic children. Patients and Methods: This cross-sectional study was conducted at a university hospital in Bangladesh. A total of 45 transfusion-dependent thalassemic children were included according to inclusion and exclusion criteria. Data collection was conducted through a structured questionnaire after taking written informed consent from each participant's guardian. Each patient underwent a detailed history taking and antibody to hepatitis B surface antigen (anti-HBs) titer was estimated to see the immune response against HepB. Results: Collected data were analyzed using SPSS version 23. The mean age of the studied children was 9.03 ± 3.78 standard deviation with slight female predominance (51.1% female and 48.9% male). According to the level of anti-HBs titer, the majority (44.4%) had moderate protection, whereas others had no (28.9%) or strong (26.7%) protection. No significant association between the total number of transfusions (approximate), different age groups, and postvaccination interval with anti-HBs titer was observed (P > 0.05). Conclusion: The present study observed an overall poor immune response against HepB as approximately only one-fourth of the study participants got strong protection against HBV. Assessment of anti-HBs titer followed by booster dose or revaccination if necessary is needed to be considered in transfusion-dependent thalassemic children vaccinated in early infancy.