title: Pneumococcal conjugate vaccine administration during therapy for pediatric leukemia.
abstract: BACKGROUND
  Pediatric leukemia patients are at high risk of invasive pneumococcal disease. The study aim was to determine the antibody response to a 10-valent pneumococcal conjugate vaccine (PCV10) administered during chemotherapy.
  
  
  METHODS
  An open-label study in pediatric leukemia patients: Group 1 had completed a primary 7-valent (PCV7) course and received a single PCV10 dose. Group 2 were PCV immunization naïve and received 3 doses of PCV10, administered 2 months apart. Serum samples were taken at baseline and 1 month post each PCV10 dose. Antipneumococcal serotype-specific IgG to 10 serotypes were measured by enzyme-linked immunosorbent assay and the functional response to 4 serotypes (1, 6B, 19F and 23F) was measured using opsonophagocytic assays.
  
  
  RESULTS
  Thirty-nine participants were recruited between May 2010 and January 2011; group 1 (n = 27) and group 2 (n = 12). The diagnosis was acute lymphoblastic leukemia (38) and acute myeloid leukemia (1). Median age was 6.2 years (1.7-17.2 years) with 62% male. The median time from diagnosis to baseline serology was 7.4 months (1.6-36.8 months). At baseline, protective geometric mean concentration above the threshold (>0.35 μg/mL) ranged from 5.3% (serotype 4) to 71% (serotype 19F). More than 60% of participants in both groups were above threshold postimmunization for 7 of the 10 PCV serotypes. Opsonophagocytic assay correlated with enzyme-linked immunosorbent assay for 3 of the 4 serotypes and r ranged from 0.51 to 0.84. An injection-site reaction was reported in 73% (27/37).
  
  
  CONCLUSIONS
  It is safe to administer PCV10 vaccine during therapy for pediatric leukemia. It provided a satisfactory serum immune response for the majority of vaccine serotypes.
authors.affiliation: From the *SAEFVIC, Murdoch Childrens Research Institute; †Department of General Medicine, Royal Children's Hospital; ‡Department of Paediatrics, The University of Melbourne; §Pneumococcal Laboratory, Murdoch Childrens Research Institute; ¶Children's Cancer Centre, Royal Children's Hospital; ‖Children's Cancer Centre and **Paediatric Infectious Diseases Unit, Monash Children's Hospital, Monash Health; and ††Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.
authors.forename: Nigel W
authors.initials: NW
authors.lastname: Crawford
authors.forename: Anne
authors.initials: A
authors.lastname: Balloch
authors.forename: Leena
authors.initials: L
authors.lastname: Tikkanen
authors.forename: Francoise
authors.initials: F
authors.lastname: Merchinaud
authors.forename: Peter
authors.initials: P
authors.lastname: Downie
authors.forename: Jim P
authors.initials: JP
authors.lastname: Buttery
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004358:Drug Therapy / Q000379:methods*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007938:Leukemia / Q000188:drug therapy* / Q000276:immunology*; D008297:Male; D009895:Opsonin Proteins / Q000097:blood; D010587:Phagocytosis; D011008:Pneumococcal Infections / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*
chemical_list: C586648:10-valent pneumococcal conjugate vaccine; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D022242:Pneumococcal Vaccines