Sustained reductions in invasive pneumococcal disease in the era of conjugate vaccine

J Infect Dis. 2010 Jan 1;201(1):32-41. doi: 10.1086/648593.


Background: Changes in invasive pneumococcal disease (IPD) incidence were evaluated after 7 years of 7-valent pneumococcal conjugate vaccine (PCV7) use in US children.

Methods: Laboratory-confirmed IPD cases were identified during 1998-2007 by 8 active population-based surveillance sites. We compared overall, age group-specific, syndrome-specific, and serotype group-specific IPD incidence in 2007 with that in 1998-1999 (before PCV7) and assessed potential serotype coverage of new conjugate vaccine formulations.

Results: Overall and PCV7-type IPD incidence declined by 45% (from 24.4 to 13.5 cases per 100,000 population) and 94% (from 15.5 to 1.0 cases per 100,000 population), respectively (P< .01 all age groups). The incidence of IPD caused by serotype 19A and other non-PCV7 types increased from 0.8 to 2.7 cases per 100,000 population and from 6.1 to 7.9 cases per 100,000 population, respectively (P< .01 for all age groups). The rates of meningitis and invasive pneumonia caused by non-PCV7 types increased for all age groups (P< .05), whereas the rates of primary bacteremia caused by these serotypes did not change. In 2006-2007, PCV7 types caused 2% of IPD cases, and the 6 additional serotypes included in an investigational 13-valent conjugate vaccine caused 63% of IPD cases among children <5 years-old.

Conclusions: Dramatic reductions in IPD after PCV7 introduction in the United States remain evident 7 years later. IPD rates caused by serotype 19A and other non-PCV7 types have increased but remain low relative to decreases in PCV7-type IPD.

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Child
  • Child, Preschool
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Humans
  • Incidence
  • Middle Aged
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / immunology
  • Pneumococcal Infections / prevention & control*
  • Pneumococcal Vaccines*
  • Population Surveillance*
  • Serotyping
  • Streptococcus pneumoniae / classification
  • United States / epidemiology
  • Young Adult


  • Heptavalent Pneumococcal Conjugate Vaccine
  • Pneumococcal Vaccines