The effect of underlying clinical conditions on the risk of developing invasive pneumococcal disease in England

J Infect. 2012 Jul;65(1):17-24. doi: 10.1016/j.jinf.2012.02.017. Epub 2012 Mar 3.


Objective: To inform national policy making on the use of the 13-valent pneumococcal vaccine among risk groups we estimated the increased risk of invasive pneumococcal disease (IPD) outcomes among clinical risk groups. Three years of post 7-valent pneumococcal conjugate vaccine (PCV7) data was included to investigate the herd protection effects.

Methods: Over 22,000 IPD patients in England (March 2002-March 2009 - aged 2 and over) were linked to their hospitalisation records. The prevalence of risk factors in these patients was compared to the prevalence of risk factors in the general population.

Results: There was an increased odds ratio (OR) for hospitalisation (OR 11.7 2-15 years; 7.6 16-64; 2.7 65+) and death (OR 2.4 2-15 years, 3.9 16-64, 1.2 65+) from IPD among risk group. The most important risk factors that predict IPD are chronic liver disease, immunosuppression, and chronic respiratory diseases. Herd protection effects due to introduction of the 7-valent vaccine were identical in both patient groups as shown by the similar decline in the proportion of IPD caused by PCV7 serotypes in risk and non-risk groups.

Conclusions: There is a marked increased risk of IPD among those with certain clinical conditions, suggesting potential benefit from a targeted vaccination approach. However, the indirect protection from conjugate vaccination of children suggests PCV vaccination of high-risk groups may not provide substantial additional benefit once herd immunity takes effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bacteremia / epidemiology*
  • Bacteremia / microbiology
  • Bacteremia / mortality
  • Bacteremia / prevention & control
  • Child
  • Child, Preschool
  • Comorbidity
  • England / epidemiology
  • Female
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Humans
  • Immunity, Herd
  • Male
  • Meningitis, Pneumococcal / epidemiology*
  • Meningitis, Pneumococcal / microbiology
  • Meningitis, Pneumococcal / mortality
  • Meningitis, Pneumococcal / prevention & control
  • Middle Aged
  • Pneumococcal Vaccines / administration & dosage
  • Pneumococcal Vaccines / immunology
  • Prevalence
  • Risk Factors
  • Streptococcus pneumoniae / immunology*
  • Streptococcus pneumoniae / pathogenicity*
  • Survival Analysis
  • Young Adult


  • 13-valent pneumococcal vaccine
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Pneumococcal Vaccines