title: Immune response to conjugated meningococcal C vaccine in pediatric oncology patients.
abstract: BACKGROUND
  Following outbreaks of meningococcal disease in Quebec in 1991-1993 and 2000-2001, a mass vaccination campaign was performed. In 2001-2002, children aged 2 months to 20 years were immunized with the Meningococcal CRM197 vaccine (Menjugate). We examined the response of pediatric oncology patients during or following maintenance chemotherapy and post-bone-marrow transplantation to Meningococcal C vaccine.
  
  
  METHODS
  This was an open label descriptive study of a cohort of patients from the oncology clinic at the Montreal Children's Hospital. A positive vaccine response was defined as a fourfold increase in specific IgG from baseline and a bactericidal assay using human complement (hBCA) titer >1:4.
  
  
  RESULTS
  Of the 25 patients with ALL, 13 had a serologic response (average 60-fold increase). The serologic responders had a higher mean B cell count (0.262) compared to non-responders 0.068 x 10.9/L [t(23) = 2.843 (P < 0.05)]. Eleven of the 12 non-responders and 4 of the responders were on maintenance chemotherapy. In addition, two of the five patients post-bone-marrow transplant, responded. Fifteen of the 34 patients (44%) had an adequate hBCA response (mean titer 61). The group included 14/18 serologic responders with hBCA response (P < 0.001) and 16/17 non-serologic responders with no hBCA response (P < 0.001).
  
  
  CONCLUSIONS
  Meningococcal C-conjugate vaccine produced variable responses in children with common cancers. Proximity to chemotherapy and total B cell number may help predict likelihood of response.
authors: Division of Pediatric Allergy and Clinical Immunology, McGill University Health Centre, Montreal, Quebec, Canada.
authors: Joyce W
authors: JW
authors: Yu
authors: Astrid
authors: A
authors: Borkowski
authors: Lisa
authors: L
authors: Danzig
authors: Stephanie
authors: S
authors: Reiter
authors: Peter
authors: P
authors: Kavan
authors: Bruce D
authors: BD
authors: Mazer
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001402:B-Lymphocytes / Q000276:immunology; D016026:Bone Marrow Transplantation; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D038542:Neisseria meningitidis, Serogroup C / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy; D012698:Serologic Tests; D013601:T-Lymphocytes / Q000276:immunology; D016896:Treatment Outcome; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate