title: Long-term immune responses to pneumococcal conjugate vaccines in children previously vaccinated with 7-valent pneumococcal conjugate vaccine.
abstract: BACKGROUND
  Seven-valent pneumococcal conjugate vaccine (PCV7) has reduced incidence of vaccine-serotype pneumococcal diseases. Using a single dose of 13-valent pneumoccal conjugate vaccine (PCV13), we evaluated late immune responses 10 years after vaccination with PCV7 in infancy, compared with a PCV7-naïve cohort.
  
  
  METHODS
  In this open-label study, we administered 1 dose of PCV13 to children aged 11-14 years who had previously received PCV7 (PCV7/PCV13) or meningococcal group C conjugate vaccine (MnCC/PCV13) during infancy. We evaluated serotype-specific immunoglobulin G concentrations and opsonophagocytic activity prevaccination and 1 week and 1 month postvaccination. We recorded local reactions and systemic events for 4 days postvaccination and adverse events for 6 months.
  
  
  RESULTS
  Seventy-four subjects received PCV13 (PCV7/PCV13, n = 38; MnCC/PCV13, n = 36). Prevaccination with PCV13, >62.9% of subjects had immunoglobulin G concentrations ≥0.35 µg/mL for all serotypes except serotype 4 (28-29%); proportions increased at 1 month postvaccination to 100% for all serotypes except serotypes 3 (PCV7/PCV13, 94.7%; MnCC/PCV13, 97.0%) and 14 (MnCC/PCV13, 97.1%). Immunoglobulin G and opsonophagocytic activity concentrations for the 7 common and 6 additional serotypes were similar in both groups prevaccination and increased in both groups from prevaccination to 1 week and 1 month postvaccination. Local reactions and fever were mild or moderate; no serious adverse events were reported.
  
  
  CONCLUSIONS
  Late immune responses after a single dose of PCV13 were similar in children aged 11-14 years regardless of previous vaccination with PCV7 or MnCC. PCV13 was immunogenic, safe and well tolerated.
authors.affiliation: From the *Kaiser Permanente Vaccine Study Center, Oakland, CA; †Formerly Pfizer Inc, Paris La Defense, France; and ‡Formerly Pfizer Inc, Collegeville, PA.
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.forename: Kathy
authors.initials: K
authors.lastname: Ensor
authors.forename: Sylvie
authors.initials: S
authors.lastname: Jouve
authors.forename: Robert
authors.initials: R
authors.lastname: Northington
authors.forename: Michele
authors.initials: M
authors.lastname: Moscariello
authors.forename: Paul C
authors.initials: PC
authors.lastname: McGovern
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood; D002648:Child; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D009895:Opsonin Proteins / Q000276:immunology; D010587:Phagocytosis; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D013997:Time Factors; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology
chemical_list: C538862:13-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate