title: Superior immune response to protein-conjugate versus free pneumococcal polysaccharide vaccine in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Debate exists about the immunogenicity and protective efficacy of antibodies produced by the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in chronic obstructive pulmonary disease (COPD). The 7-valent diphtheria-conjugated pneumococcal polysaccharide vaccine (PCV7) induces a more robust immune response than PPSV23 in healthy elderly adults.
  
  
  OBJECTIVE
  We hypothesized that serotype-specific IgG antibody concentration and functional antibody activity would be superior after PCV7 vaccination compared with PPSV23 in moderate to severe COPD. We also posited that older age and prior PPSV23 vaccination would be associated with reduced vaccine responsiveness.
  
  
  METHODS
  One hundred twenty patients with COPD were randomized to PPSV23 (63 subjects) or PCV7 (57 subjects). IgG concentrations were determined by ELISA; functional antibody activity was assayed with a standardized opsonophagocytosis assay and reported as an opsonization killing index (OPK). Increases in serotype-specific IgG and OPK at 1 month post vaccination were compared within and between vaccine groups.
  
  
  RESULTS
  Both vaccines were well tolerated. Within each study group, postvaccination IgG and OPK were higher than baseline (P < 0.01) for all serotypes. Adjusted for baseline levels, postvaccination IgG was higher in the PCV7 group than the PPSV23 group for all seven serotypes, reaching statistical significance for five (P < 0.05). PCV7 resulted in a higher OPK for six of seven serotypes (statistically greater for four) compared with PPSV23. In multivariate analyses, younger age, vaccine naivety, and receipt of PCV7 were associated with increased OPK responses.
  
  
  CONCLUSIONS
  PCV7 induces a superior immune response at 1 month post vaccination compared with PPSV23 in COPD. Older age and prior PPSV23 reduce vaccine responsiveness. Clinical trial registered with www.clinicaltrials.gov (NCT00457977).
authors: Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA. mdransfield99@msn.com
authors: Mark T
authors: MT
authors: Dransfield
authors: Moon H
authors: MH
authors: Nahm
authors: Meilan K
authors: MK
authors: Han
authors: Sarah
authors: S
authors: Harnden
authors: Gerard J
authors: GJ
authors: Criner
authors: Fernando J
authors: FJ
authors: Martinez
authors: Paul D
authors: PD
authors: Scanlon
authors: Prescott G
authors: PG
authors: Woodruff
authors: George R
authors: GR
authors: Washko
authors: John E
authors: JE
authors: Connett
authors: Nicholas R
authors: NR
authors: Anthonisen
authors: William C
authors: WC
authors: Bailey
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000276:immunology* / Q000517:prevention & control; D012907:Smoking / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000472:pathogenicity
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D007073:Immunoglobulin E