title: Immunization practices in acute lymphocytic leukemia and post-hematopoietic stem cell transplant in Canadian Pediatric Hematology/Oncology centers.
abstract: There are no Canadian immunization guidelines for children treated for malignancy. Guidelines do exist for patients who underwent hematopoietic stem cell transplant (HSCT), but they provide broad timeframes for initiating vaccination; there is no standard schedule. The optimal approach to immunization in these populations is unclear. We sought to describe immunization practices at Canadian Pediatric Hematology/Oncology centers. A 43-item online questionnaire was distributed to the 16 programs in the C(17) research network of pediatric hematology/oncology centers to capture information on timing and criteria for immunization of patients with acute lymphocytic leukemia (ALL) and those who have undergone HSCT. At each center, 1-2 physicians or pharmacists completed the survey to reflect center-wide immunization practices. Responses were received from 11/16 (69%) programs; 11 respondents reported on practices for patients with ALL and 9 reported on practices for patients who are post-HSCT. In 5/11 ALL programs (45%) re-immunization is recommended routinely after chemotherapy, starting 3-6 months post-chemotherapy. In HSCT programs, timing of pneumococcal conjugate vaccination (PCV) varied from 3 months post-HSCT (4 programs) to 12 months post-HSCT (4 programs). Live vaccines were administered 24 months post-HSCT in 8/9 programs. All HSCT programs considered graft-versus-host-disease and 7 considered discontinuation of immunosuppression in immunization decisions. Pediatric hematology/oncology programs were divided in regards to re-immunization of patients with ALL post-chemotherapy. After HSCT, timing of PCV administration varied, with 4 programs initiating immunization later than Canadian guidelines recommend (3-9 months post-HSCT). These findings suggest a need to standardize immunization practices in these populations.
authors.affiliation: a Department of Pediatrics , Dalhousie University , Halifax , NS , Canada.|b Canadian Center for Vaccinology, IWK Health Centre , Halifax , NS , Canada.
authors.forename: Karina A
authors.initials: KA
authors.lastname: Top
authors.affiliation: c Department of Pediatrics , University of Ottawa and Children's Hospital of Eastern Ontario , Ottawa , ON , Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Pham-Huy
authors.affiliation: a Department of Pediatrics , Dalhousie University , Halifax , NS , Canada.
authors.forename: Victoria
authors.initials: V
authors.lastname: Price
authors.affiliation: d Department of Pediatrics , University of Toronto and Hospital for Sick Children , Toronto , ON , Canada.
authors.forename: Lillian
authors.initials: L
authors.lastname: Sung
authors.affiliation: d Department of Pediatrics , University of Toronto and Hospital for Sick Children , Toronto , ON , Canada.
authors.forename: Dat
authors.initials: D
authors.lastname: Tran
authors.affiliation: e Department of Pediatrics , University of Alberta and Stollery Children's Hospital , Edmonton , AB , Canada.
authors.forename: Wendy
authors.initials: W
authors.lastname: Vaudry
authors.affiliation: a Department of Pediatrics , Dalhousie University , Halifax , NS , Canada.|b Canadian Center for Vaccinology, IWK Health Centre , Halifax , NS , Canada.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Halperin
authors.affiliation: f Institut National de Santé Publique du Québec , Québec , QC , Canada.
authors.forename: Gaston
authors.initials: G
authors.lastname: De Serres
mesh_terms: D000293:Adolescent; D002170:Canada; D002648:Child; D005260:Female; D006405:Hematology; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007114:Immunization; D016867:Immunocompromised Host; D007165:Immunosuppression Therapy; D008297:Male; D010372:Pediatrics; D010818:Practice Patterns, Physicians'; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000628:therapy; D011795:Surveys and Questionnaires; D014612:Vaccines / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D014612:Vaccines
keywords: acute lymphoblastic leukemia; chemotherapy; immunization; pediatric; stem cell transplant; vaccination