title: Comparison of pneumococcal conjugate polysaccharide and free polysaccharide vaccines in elderly adults: conjugate vaccine elicits improved antibacterial immune responses and immunological memory.
abstract: BACKGROUND
  High functional antibody responses, establishment of immunologic memory, and unambiguous efficacy in infants suggest that an initial dose of conjugated pneumococcal polysaccharide (PnC) vaccine may be of value in a comprehensive adult immunization strategy.
  
  
  METHODS
  We compared the immunogenicity and safety of 7-valent PnC vaccine (7vPnC) with that of 23-valent pneumococcal polysaccharide vaccine (PPV) in adults >/=70 years of age who had not been previously vaccinated with a pneumococcal vaccine. One year later, 7vPnC recipients received a booster dose of either 7vPnC (the 7vPnC/7vPnC group) or PPV (the 7vPnC/PPV group), and PPV recipients received a booster dose of 7vPnC (the PPV/7vPnC group). Immune responses were compared for each of the 7 serotypes common to both vaccines.
  
  
  RESULTS
  Antipolysaccharide enzyme-linked immunosorbent assay antibody concentrations and opsonophagocytic assay titers to the initial dose of 7vPnC were significantly greater than those to the initial dose of PPV for 6 and 5 of 7 serotypes, respectively (P < .01 and P < .05, respectively). 7vPnC/7vPnC induced antibody responses that were similar to those after the first 7vPnC inoculation, and 7vPnC/PPV induced antibody responses that were similar to or greater than antibody responses after administration of PPV alone; PPV/7vPnC induced significantly lower antibacterial responses, compared with those induced by 7vPnC alone, for all serotypes (P < .05).
  
  
  CONCLUSIONS
  In adults, an initial dose of 7vPnC is likely to elicit higher and potentially more effective levels of antipneumococcal antibodies than is PPV. In contrast with PPV, for which the induction of hyporesponsiveness was observed when used as a priming dose, 7vPnC elicits an immunological state that permits subsequent administration of 7vPnC or PPV to maintain functional antipolysaccharide antibody levels.
authors.affiliation: Center for Respiratory Medicine at the Charlottenburg Castle, Charité Universitätsmedizin Berlin, Berlin, Germany. aderoux@aol.com
authors.forename: Andrés
authors.initials: A
authors.lastname: de Roux
authors.forename: B
authors.initials: B
authors.lastname: Schmöle-Thoma
authors.forename: B
authors.initials: B
authors.lastname: Schmöele-Thoma
authors.forename: G R
authors.initials: GR
authors.lastname: Siber
authors.forename: J G
authors.initials: JG
authors.lastname: Hackell
authors.forename: A
authors.initials: A
authors.lastname: Kuhnke
authors.forename: N
authors.initials: N
authors.lastname: Ahlers
authors.forename: S A
authors.initials: SA
authors.lastname: Baker
authors.forename: A
authors.initials: A
authors.lastname: Razmpour
authors.forename: E A
authors.initials: EA
authors.lastname: Emini
authors.forename: P D
authors.initials: PD
authors.lastname: Fernsten
authors.forename: W C
authors.initials: WC
authors.lastname: Gruber
authors.forename: S
authors.initials: S
authors.lastname: Lockhart
authors.forename: O
authors.initials: O
authors.lastname: Burkhardt
authors.forename: T
authors.initials: T
authors.lastname: Welte
authors.forename: H M
authors.initials: HM
authors.lastname: Lode
mesh_terms: D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007117:Immunization, Secondary; D007156:Immunologic Memory; D008297:Male; D022401:Meningococcal Vaccines / Q000009:adverse effects / Q000276:immunology*; D010587:Phagocytosis; D022242:Pneumococcal Vaccines / Q000009:adverse effects / Q000276:immunology*
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022401:Meningococcal Vaccines; D022242:Pneumococcal Vaccines