Immunogenicity of varying dosages of 7-valent pneumococcal polysaccharide-protein conjugate vaccine in seniors previously vaccinated with 23-valent pneumococcal polysaccharide vaccine

Vaccine. 2007 May 16;25(20):4029-37. doi: 10.1016/j.vaccine.2007.02.062. Epub 2007 Mar 12.


In this dose-ranging study 220 seniors who had received the 23-valent pneumococcal polysaccharide (PnPS) vaccine at least 5 years prior to enrollment were assigned to receive one of four volumes (0.1, 0.5, 1 or 2 ml) of 7-valent pneumococcal conjugate (PnC) vaccine or a 0.5 ml dose of 23-valent PnPS vaccine. All participants received a reduced challenge dose of 0.1 ml of PnPS vaccine 1 year after enrollment. There was evidence of a dose response to PnC vaccine and antibody levels in the 1 ml PnC group tended to be significantly higher than in the PnPS group. A booster response to the challenge vaccination was not observed. Administration of a 1 ml dose of PnC vaccine is more immunogenic than 0.5 ml of PnPS vaccine in elderly adults previously vaccinated with PnPS vaccine.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Antibodies, Bacterial / biosynthesis
  • Antibodies, Bacterial / blood
  • Dose-Response Relationship, Immunologic
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Humans
  • Male
  • Meningococcal Vaccines / administration & dosage*
  • Meningococcal Vaccines / adverse effects
  • Pneumococcal Vaccines / administration & dosage*
  • Pneumococcal Vaccines / adverse effects


  • Antibodies, Bacterial
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Meningococcal Vaccines
  • Pneumococcal Vaccines