title: Efficacy of primary hepatitis B immunization in children with acute lymphoblastic leukemia.
abstract: BACKGROUND
  Children with acute lymphoblastic leukemia (ALL) carry a high risk of hepatitis B virus (HIV) infection. The present study was conducted to see if prior routine hepatitis B vaccine received as a part of national immunization program could prevent HBV infection in these children.
  
  
  METHODS
  Ninety-six children with ALL were screened for HBV. Children were divided into three groups according to their initial HBV serology; previously vaccinated children (Group I) (n=34) previously unvaccinated and seronegative children (Group II) (n=56),and unvaccinated but HBsAg negative and anti-HBs positive children (group III) (n=6). Sixty-seven of 96 (69.7%) children received vaccination. The schedule was initiated during the third month of maintenance therapy and each course consisted of three doses given at one month interval.
  
  
  RESULTS
  Anti-HBs seroconversion following the first course of three doses of hepatitis B vaccination in group I, II and III was 57%, 33% and 100%, respectively. It increased to 97% in Group I, 62.5% in Group II, 100% in Group III. HBsAg positivity was found in 11 children (11.5%) and all of them developed chronic hepatitis B. Ten of them were in Group II whereas only one child was in Group I (P<0.04).
  
  
  CONCLUSIONS
  This data reveals that routine HBV vaccination within the national immunization program plays an important role in decreasing subsequent hepatitis B infection in children with ALL.
authors.affiliation: Department of Pediatric Hematology, Uludag University, Medical Faculty, bursa, Turkey. baytanbirol@yahoo.com
authors.forename: Birol
authors.initials: B
authors.lastname: Baytan
authors.forename: Adalet Meral
authors.initials: AM
authors.lastname: Gunes
authors.forename: Unsal
authors.initials: U
authors.lastname: Gunay
mesh_terms: D000367:Age Factors; D002648:Child; D002669:Child Welfare; D018450:Disease Progression; D005260:Female; D006304:Health Status; D006509:Hepatitis B / Q000276:immunology / Q000503:physiopathology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D006801:Humans; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000503:physiopathology*; D012074:Remission Induction; D012307:Risk Factors
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines