title: Randomized, single blind, controlled trial to evaluate the prime-boost strategy for pneumococcal vaccination in renal transplant recipients.
abstract: Renal transplant recipients are at increased risk of developing invasive pneumococcal diseases but may have poor response to the 23-valent pneumococcal polysaccharide vaccine (PPV). It may be possible to enhance immunogenicity by priming with 7-valent pneumococcal conjugate vaccine (7vPnC) and boosting with PPV 1 year later. In a randomized single-blind, controlled study, adult recipients of renal transplants received either 7nPVC or PPV followed by PPV 1 year later. The vaccine response was defined as 2-fold increase in antibody concentration from baseline and an absolute post-vaccination values ≥1 µg/ml. The primary endpoint was vaccine response of the primed group (7vPnC/PPV) compared with single PPV vaccination. Antibody concentrations for 10 serotypes were measured at baseline, 8 weeks after first vaccination, before second vaccination, and 8 weeks after second vaccination. Of 320 screened patients, 80 patients were randomized and 62 completed the study. Revaccination with PPV achieved no significant increase of immune response in the 7vPnC/PPV group compared with the single PPV recipients A response to at least 1 serotype was seen in 77.1% of patients who received 7vPnC and 93.1% of patients who received PPV (P = 0.046). After second vaccination response to at least 1 serotype was seen in 87.5% patients of 7vPnC/PPV group and 87.1% patients of PPV group (non significant p). The median number of serotypes eliciting a response was 3.5 (95% CI 2.5-4.5) in the 7vPnC/PPV group versus 5 (95% CI 3.9-6.1) in the PPV group (non-significant p). Immunogenicity of pneumococcal vaccination was not enhanced by the prime-boost strategy compared with vaccination with PPV alone. Administration of a single dose of PPV should continue to be the standard of care for adult recipients of renal transplants.
  
  
  BACKGROUND
  EudraCT 2007-004590-25.
authors.affiliation: Department of Internal Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Austria.
authors.forename: Selma
authors.initials: S
authors.lastname: Tobudic
authors.forename: Veronika
authors.initials: V
authors.lastname: Plunger
authors.forename: Gere
authors.initials: G
authors.lastname: Sunder-Plassmann
authors.forename: Markus
authors.initials: M
authors.lastname: Riegersperger
authors.forename: Heinz
authors.initials: H
authors.lastname: Burgmann
mesh_terms: D000328:Adult; D000368:Aged; D000917:Antibody Formation; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000276:immunology / Q000627:therapeutic use*; D018074:Vaccines, Conjugate / Q000276:immunology / Q000627:therapeutic use*
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate