title: Protection against vaccine preventable diseases in children treated for acute lymphoblastic leukemia.
abstract: The objective of this retrospective study was to assess protection against vaccine preventable diseases (VPDs) in children treated for acute lymphoblastic leukemia (ALL).
  
  
  
  Clinical characteristics and vaccination records were collected. Antibodies against VPDs were measured after completion of chemotherapy and after a booster dose of vaccine. Immunization status of household members was evaluated.
  
  
  
  Sixty children were included. Median interval between the end of chemotherapy and enrolment in the study was 13 months (range 1-145). At ALL diagnosis, 81.3% of the children were up to date with their vaccination schedule. This proportion decreased to 52.9% at enrolment. Among the parents, 21% were up to date with their immunization schedule and 42% had received seasonal influenza vaccination. After chemotherapy, less than 50% of the patients were seroprotected against tetanus, diphtheria, polio 3, Haemophilus influenzae type b (Hib), and mumps and no more than 80% were seroprotected against polio 1 and 2, measles, rubella, and varicella. After a booster dose of vaccine, the rate of protection increased to over 90% for each of the following antigens: TT, DT, polio 1, Hib, measles, and rubella. Nevertheless, polio 3, mumps, and varicella-zoster virus antibodies titers/concentrations remained below seroprotective thresholds in over 20% of the patients.
  
  
  
  After chemotherapy for ALL, most of the children were not protected against VPDs. As the majority mounted a robust response to booster vaccines, efforts need to be done to improve protection against VPDs by implementing a systematic vaccine booster schedule. This could also be helped by reinforcing household members' immunization.
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Isabel
authors.initials: I
authors.lastname: de de la Fuente Garcia
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Léna
authors.initials: L
authors.lastname: Coïc
authors.affiliation: Division of Hematology-Oncology, Department of Pediatrics, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Leclerc
authors.affiliation: Division of Hematology-Oncology, Department of Pediatrics, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Laverdière
authors.affiliation: Department of Microbiology and Immunology, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Céline
authors.initials: C
authors.lastname: Rousseau
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ovetchkine
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, CHU Sainte-Justine-Université de Montréal, Montréal, Québec, Canada.
authors.forename: Bruce
authors.initials: B
authors.lastname: Tapiéro
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000276:immunology / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary / Q000379:methods*; D007223:Infant; D008297:Male; D009367:Neoplasm Staging; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D014612:Vaccines / Q000276:immunology / Q000627:therapeutic use*; D014777:Virus Diseases / Q000276:immunology / Q000517:prevention & control*
chemical_list: D000914:Antibodies, Viral; D014612:Vaccines
keywords: chemotherapy; children; immunization; leukemia; vaccination coverage