Use of procalcitonin and C-reactive protein to evaluate vaccine efficacy against pneumonia.
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.
Madhi
Shabir A
SA
National Health Laboratory Service, University of The Witwatersrand, Johannesburg, South Africa. madhis@hivsa.com
Heera
Jayvant R
JR
Kuwanda
Locadiah
L
Klugman
Keith P
KP
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
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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