Community-acquired pneumonia: pneumococcal vaccine decreases pneumococcal pneumonia.

Clinical bottom line (level 1a)

  1. Adult patients given a pneumococcal vaccine are less likely to contract definitive or presumptive pneumococcal pneumonia than those given placebo.
  2. There is no clear difference in all cause pneumonia, bronchitis and mortality.
Fine et al: Archives of Internal Medicine 1994; 154: 2666-2677
Expires March 2003

The study

Systematic review of Randomised controlled trials, case-control studies, cost-effectiveness analyses or studies. of
  • Patients: adults
  • Intervention: pneumococcal vaccine compared with placebo
  • Outcome: pneumonia


    • Articles found in English or non-English using MEDLINE, 1966 to 1991 (search terms: explode pneumococcal infections and explode immunization or explode vaccines ) and Bibliographies of all retrieved articles were reviewed to obtain pertinent articles not identified in MEDLINE. Wrote to leading authors of all identified randomized controlled and case-controls studies, and to the vaccine's two pharmaceutical manufacturers (Merck Sharpe and Dohme and Lederle Laboratories) to identify any remaining published or unpublished randomized controlled studies.

    Selection criteria: as above
    Appraisal criteria: detailed in text
    Articles excluded if: Randomised controlled trials that evaluated pneumococcal vaccines of four or fewer valences; trials in paediatric patients; cohort studies or case reports; cost-effectiveness studies; controlled, nonrandomised studies; reprints of previously published material; case-control studies; other types of studies of pneumococcal infection

    Nine randomised trials were included.
    Q statistics revealed significant heterogeneity for all four of the pneumococcal infection-related outcomes in which two or more studies reported data, including definitive pneumococcal pneumonia (vaccine types only), definitive pneumococcal pneumonia, presumptive pneumococcal pneumonia and presumptive pneumococcal pneumonia (vaccine types only).

    The evidence

    Outcome Time to outcome CER OR
    (95% CI)    		 NN?
    (% CI)
    definitive pneumococcal pneumonia unknown /
    (%)    		 0.34
    (0.24 to 0.48)
    definitive pneumococcal pneumonia (vaccine-containing pneumococcal antigen types only) unknown /
    (%)    		 0.17
    (0.09 to 0.33)
    presumptive pneumococcal pneumonia unknown /
    (%)    		 0.47
    (0.35 to 0.63)
    presumptive pneumococcal pneumonia (vaccine-containing pneumococcal types only) unknown /
    (%)    		 0.39
    (0.26 to 0.59)
    pneumonia (all causes) unknown /
    (%)    		 0.90
    (0.77 to 1.04)
    bronchitis unknown /
    (%)    		 0.84
    (0.69 to 1.02)
    mortality (all causes) unknown /
    (%)    		 1.02
    (0.90 to 1.14)
    mortality (due to pneumonia) unknown /
    (%)    		 0.78
    (0.57 to 1.06)
    mortality (due to pneumococcal infection) unknown /
    (%)    		 4.59
    (0.54 to 38.8)

    Comments

    1. There is no clear difference in mortality due to pneumococcal infection, but there is a trend towards it being more likely with a pneumococcal vaccine.
    2. High-risk groups appear to have less benefit from vaccination

    Citation

    1. Fine MJ, Smith MA, Carson CA, et al: Efficacy of pneumococcal vaccination in adults: A meta-analysis of randomized controlled trials. Archives of Internal Medicine 1994; 154: 2666-2677
    Search Terms: pneumonia and vaccine in Medline
    Contributor: Clare Wotton and Musab Hayatli, November 1999
    Reviewer: Chris van Weel

    Clinical Question.
    Patient adults
    Intervention or Exposure pneumococcal vaccination
    Comparison placebo
    Outcome pneumonia