13-Valent pneumococcal conjugate vaccine (PCV13) in children partially immunized with 7-valent pneumococcal conjugate vaccine (PCV7): A phase 3, open-label trial

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Background: As 13-valent pneumococcal conjugate vaccine (PCV13) is introduced, children who began vaccination with 7-valent pneumococcal conjugate vaccine (PCV7) may complete their vaccination with PCV13. This open-label phase 3 study evaluated immunogenicity and safety of PCV13 in Swedish infants and toddlers previously given 1 or 2 doses of PCV7 during infancy. Methods: Healthy infants previously given PCV7 at ages 3 months (group 1; n = 118) or 3 and 5 months (group 2; n = 116) received PCV13 at ages 5 (group 1) and 12 months (both groups). IgG responses were assessed 1 month after each PCV13 dose and before the 12-month dose. Local reactions and systemic events were collected for 7 days postvaccination. Other adverse events were also collected. Results: Post-5-month dose, IgG geometric mean concentrations (GMCs) in group 1 were 1.56-4.70 mu g/ml for most PCV7 serotypes except 6B (0.40 mu g/ml) and 23F (0.57 mu g/ml) and 0.72-1.88 mu g/ml for most of the 6 additional serotypes, except 6A (0.28 mu g/ml). Post-12-month dose, IgG GMCs for the PCV7 serotypes were 2.93-9.63 mu g/ml (group 1) and 3.33-9.30 mu g/ml (group 2); and for the 6 additional serotypes, 1.85-14.65 mu g/ml (group 1) and 1.34-13.16 mu g/ml (group 2). GMCs increased by >4-fold in both groups from pre- to post-12-month dose. Proportions of subjects in group 1 with pneumococcal serotype-specific IgG concentrations >= 0.35 mu g/ml (WHO-designated postprimary reference antibody level) post-5-month dose were 92.2-99.1% for most PCV7 serotypes except 6B (53.0%) and 23F (62.6%) and 80.9-100.0% for most of the 6 additional serotypes except 6A (36.8%). Local reactions and fever were mostly mild or moderate. Conclusions: PCV13 was immunogenic and safe in infants and toddlers previously partially immunized with PCV7. Even a single dose in an infant or toddler induces an immune response to the 6 additional serotypes. (C) 2013 Published by Elsevier Ltd.


  • Sven Arne Silfverdal
  • Carl-Erik Flodmark
  • Lars Rombo
  • Susan P. Tansey
  • Mohinder Sidhu
  • James Trammel
  • Emilio A. Emini
  • William C. Gruber
  • Daniel A. Scott
  • Alejandra Gurtman
External organisations
  • Umeå University
  • Karolinska Institutet
  • Pfizer Limited, UK
  • PharmaNet Development Group Inc.
  • Pfizer Inc. US
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Pediatrics
  • Immunology in the medical area
  • Medicinal Chemistry


  • 13-Valent pneumococcal conjugate vaccine, Pediatric, Immunogenicity, Safety, PCV13, 2+1 Schedule
Original languageEnglish
Pages (from-to)1284-1292
Issue number9
Publication statusPublished - 2013
Publication categoryResearch