Spread of hepatitis B virus (HBV) continues to be at an alarming rate worldwide, and this created an impact on many countries. Even with the presence of effective vaccines, hepatitis B remains a stubborn, unrelenting health problem, especially in Africa and other developing areas. Studies in the Middle East showed that the prevalence of HBsAg ranged from 3 to 11% in Egypt. Patients on repeated blood transfusion are at high risk for acquiring HBV infection. The aim of the work was evaluation of hepatitis B vaccination protection in both healthy and polytransfused Egyptian children with β-thalassemia major.Methods
Cross-sectional study was conducted on 200 Egyptian children; 100 of them were known to have β-thalassemia major, receiving packed transfusion more than 10 times and documented to be vaccinated by the recombinant hepatitis B vaccine applied by the Ministry of Health at 2, 4, and 6 months of age, and 100 healthy children with matched age and sex also documented to be vaccinated according to the same schedule served as the control group. Samples were collected from all children for HBsAb titer level by enzyme-linked immunosorbent assay test, and questionnaire was designed to collect the risk factors data.Results
(a) The mean anti-HBs titer was significantly higher among healthy children than in thalassemic cases. (b) Thalassemic children with age range from 7 to 12 years had the lowest mean serum anti-HBs levels. (c) There was significant negative correlation between postvaccination intervals in healthy as well as thalassemic children and the mean level of anti-HBs titer. (d) There was significant negative correlation between number of blood transfusions in thalassemic children and the mean level of anti-HBs titer.Conclusion
Anti-HBs titer wanes with time lapse and became not enough to be immunogenic in a high percentage of thalassemic children especially after the age of 7 years.Recommendations
Booster dose to all multitransfused thalassemic children beyond 2 years of vaccination is recommended. Healthy children aged 7 years or more need booster dose of HBV vaccine to achieve complete immune response.