Prevalence of Hepatitis Virus Infection and Immunogenicity of HBV Vaccine in Children with Down's Syndrome

Abstract

The prevalence of Hepatitis A, B and C infection was assessed in sixty children with Down's syndrome (DS) and compared with sixty children with normal mentality by screening for HBsAg, HBeAg, anti-HBe, anti-HBc, anti-HBs and anti-HCVand HAV-Ig. Both groups had received three doses of recombinant DNA hepatitis vaccine at 0,1 and 6 months of age. None of the children in either group were found to have any hepatitis viral antiginaemia, hepatitis marker or to have chronic viral hepatitis. Hepatitis B vaccine protective efficacy which was es-tablished by the presence of anti-HBs >10 mil], was sig-nificantly lower in the DS than the control group (28.3% Vs 85%,p < 0.001). None of the children in the DS group, after the age of seven years, had protective anti-HBs level as compared to 79% of the children in the control group. Booster doses are not recommended for normal chil-dren even if they lose their antibody to HBV vaccine be-cause of the presence of immune memory. However, in children with DS, because of their immune deficiency, low vaccination response, and their predisposition to chronic hepatitis infection especially at school age, we recommend booster HBV vaccination for them at school entry.