Efficacy of HBV Vaccination in Children with Thalassemia Major, South Khorasan, Iran

Background: Thalassemia patients are more susceptible to hepatitis than the normal population due to the frequent blood transfusion. This study was performed to determine the immune response of children with major β-thalassemia, by measuring anti-HBS antibody following the last HBV vaccine injection. Methods: This study was carried out on all thalassemic children under the care of Iran Thalassemia Foundation (38 cases) in Birjand, receiving three standard intramuscular recombinant HBV vaccines. The children’s mean age was 9.2±4.6 years. Based on the time lapsed since their last vaccine injection, the subjects were divided into two groups of ≤5 years and >5 years. Based on the serum level of anti-HBS-antibody, the subjects were categorized as good responders (anti-HBS>100 IU/lit), low (anti-HBS=10-100 IU/lit), and non-responders (anti-HBS<10 IU/lit). Results: The mean ranges of anti-HBS level in the above-mentioned groups were 99.7 and 43.3 IU/lit, respectively. Out of 38 individuals, 13 (34.2%) were good responders, 9 (23.7%) low and 16 (42.1%) non responders. Conclusion: Standard HBV vaccination in thalassemic children results in an immune response in 57.9% of subjects. Therefore, assessment of anti-HBS-antibody 5 years after the last vaccination is recommended.