Safety and efficacy of the seven-valent pneumococcal conjugate vaccine: evidence from Northern California

Eur J Pediatr. 2002 Dec;161 Suppl 2:S127-31. doi: 10.1007/s00431-002-1064-z. Epub 2002 Nov 9.


Pneumococcal disease remains a significant cause of morbidity among young children. A large-scale efficacy trial in the Northern California Kaiser Permanente system (the KP trial) demonstrated that a seven-valent conjugate vaccine (PCV) is safe and immunogenic in young children and effective in preventing both invasive pneumococcal disease caused by vaccine serotypes (97.4% efficacy) and episodes of otitis media (7.0% efficacy). Since the publication of the results of the KP trial in 2000, we have performed an additional analysis on the safety, immunogenicity, and efficacy of the vaccine in low birth weight (LBW) and preterm (PT) infants, and have examined the efficacy of the vaccine during 1 year of wide-scale post-licensure use. The vaccine was at least as immunogenic in LBW and PT infants as in normal-weight, full-term infants and was 100% effective, although the LBW and PT infants had higher rates of adverse events such as redness and swelling. LBW and PT infants receiving pneumococcal vaccine also had higher rates of adverse events, such as hives, than those receiving control meningococcal vaccine, but these reactions were not severe. When the PCV was used in the general population, the efficacy remained high and there was no corresponding increase in disease caused by nonvaccine serotypes. There was also evidence that vaccine administration led to herd immunity. Febrile illness was the only adverse event seen more frequently after vaccine administration than during a control period.

Conclusion: the seven-valent conjugate vaccine is safe and effective for use in the general population.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Birth Weight
  • Child Welfare
  • Child, Preschool
  • Double-Blind Method
  • Evidence-Based Medicine
  • Gestational Age
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Humans
  • Immunogenetics
  • Infant
  • Infant Welfare
  • Infant, Newborn
  • Meningococcal Vaccines / adverse effects
  • Meningococcal Vaccines / immunology
  • Meningococcal Vaccines / therapeutic use*
  • North Carolina
  • Otitis Media / immunology
  • Otitis Media / prevention & control
  • Patient Admission
  • Pneumococcal Vaccines / adverse effects
  • Pneumococcal Vaccines / immunology
  • Pneumococcal Vaccines / therapeutic use*
  • Pneumonia, Pneumococcal / immunology
  • Pneumonia, Pneumococcal / prevention & control
  • Serotyping
  • Severity of Illness Index
  • Streptococcus pneumoniae / classification
  • Treatment Outcome


  • Heptavalent Pneumococcal Conjugate Vaccine
  • Meningococcal Vaccines
  • Pneumococcal Vaccines