title: Use of procalcitonin and C-reactive protein to evaluate vaccine efficacy against pneumonia.
abstract: BACKGROUND
  Pneumonia remains the leading cause of death in young children. The poor specificity of chest radiographs (CXRs) to diagnose pneumococcal pneumonia may underestimate the efficacy of pneumococcal conjugate vaccine in preventing pneumococcal pneumonia.
  
  
  RESULTS
  The efficacy of nine-valent pneumococcal conjugate vaccine among children not infected with HIV (21%; 95% confidence interval, 1%-37%) increased when CXR-confirmed pneumonia was associated with serum C-reactive protein of 120 mg/l (12 mg/dl) or more and procalcitonin of 5.0 ng/ml or more (64%; 95% confidence interval, 23%-83%). Similar results were observed in children infected with HIV.
  
  
  CONCLUSIONS
  C-reactive protein and procalcitonin improve the specificity of CXR to diagnose pneumococcal pneumonia and may be useful for the future evaluation of the effectiveness of pneumococcal conjugate vaccine in preventing pneumococcal pneumonia.
authors.affiliation: National Health Laboratory Service, University of The Witwatersrand, Johannesburg, South Africa. madhis@hivsa.com
authors.forename: Shabir A
authors.initials: SA
authors.lastname: Madhi
authors.forename: Jayvant R
authors.initials: JR
authors.lastname: Heera
authors.forename: Locadiah
authors.initials: L
authors.lastname: Kuwanda
authors.forename: Keith P
authors.initials: KP
authors.lastname: Klugman
mesh_terms: D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002648:Child; D004311:Double-Blind Method; D015658:HIV Infections / Q000150:complications; D006801:Humans; D010919:Placebos; D022242:Pneumococcal Vaccines / Q000276:immunology / Q000627:therapeutic use*; D011018:Pneumonia, Pneumococcal / Q000175:diagnosis / Q000517:prevention & control*; D011498:Protein Precursors / Q000097:blood*; D013902:Radiography, Thoracic; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D010919:Placebos; D022242:Pneumococcal Vaccines; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide
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