Determination of Hepatitis B Surface Antibody Titer in Vaccinated Children with Major Thalassemia in Kerman-Iran

Background: Thalassemia patients are more susceptible to hepatitis than the normal population due to the frequent blood transfusions. Objective: To determine the immune response of children with major ß-thalassemia, by measuring anti-hepatitis B surface antibody (anti-HBs Ab) following the last HBV vaccine injection. Methods: This study was carried out on 215 thalassemic children who received three standard intramuscular recombinant HBV vaccines. Children age ranged between 1-4.5 with a mean age of 3.37 years. Based on the time lapsed since last vaccine injection, the subjects were divided into three groups; 0-15 months, 15-30 months and 30-45 months, respectively. Based on the serum levels of anti-HBs antibody, subjects were categorized as: good responders (anti-HBs >100 IU/Lit), low responders (anti-HBs 10-100 IU/Lit) and non-responders (anti-HBs <10 IU/Lit). Results: The mean range of anti-HBs level in the above mentioned groups were 205.34, 128.8 and 54.25 IU/lit, respectively (P<0.0001). In girls, the mean antibody level was 104.2 and in boys it was 95.8 IU/Lit (P>0.05). Out of 215 selected individuals 75 (35%) were good responders, 65(30%) low responders and 75 (35%) non-responders. Conclusion: Standard HBV vaccination in thalassemic children results in an immune response in more than 65% of the subjects. Therefore, assessment of anti-HBs antibody level, 45 months after the last vaccination, is recommended