Tuesday June 2, 2009
Is There a Real Role of Pneumococcal Vaccine ?

Administrating pneumococcal vaccine has been the part of core measure as mandated by JCAHO and several other regulatory agencies. Efforts have been initiated by several centers to ensure pneumococcal vaccine resulting in several doses over a period of few years in patients who are poor historian and have received that vaccination at their physician’s office. Metaanalysis by Huss helped once again to clarify the over-exaggerated efforts.

Introduction: Clinical trials and meta-analyses have produced conflicting results of the efficacy of unconjugated pneumococcal polysaccharide vaccine in adults.

METHODS: Meta-analyses for clinical trials that compared pneumococcal polysaccharide vaccine with a control. They examined rates of pneumonia and death, taking the methodological quality of the trials into consideration. They included 22 trials involving 101 507 participants: 11 trials reported on presumptive pneumococcal pneumonia, 19 on all-cause pneumonia and 12 on all-cause mortality. The current 23-valent vaccine was used in 8 trials.

RESULTS:

• The relative risk (RR) was 0.64 (95% confidence interval [CI] 0.43-0.96) for presumptive pneumococcal pneumonia and 0.73 (95% CI 0.56-0.94) for all-cause pneumonia.
• There was significant heterogeneity between the trials reporting on presumptive pneumonia (I(2) = 74%) and between those reporting on all-cause pneumonia (I(2) = 90%).
• The RR for all-cause mortality was 0.97 (95% CI 0.87-1.09), with moderate heterogeneity between trials (I(2) = 44%, p = 0.053). Trial quality, especially regarding double blinding, explained a substantial proportion of the heterogeneity in the trials reporting on presumptive pneumonia and all-cause pneumonia.
• There was little evidence of vaccine protection in trials of higher methodologic quality (RR 1.20, 95% CI 0.75-1.92, for presumptive pneumonia; and 1.19, 95% CI 0.95-1.49, for all-cause pneumonia in double-blind trials).
• The results for all-cause mortality in double-blind trials were similar to those in all trials combined.
• There was little evidence of vaccine protection among elderly patients or adults with chronic illness in analyses of all trials (RR 1.04, 95% CI 0.78-1.38, for presumptive pneumococcal pneumonia; 0.89, 95% CI 0.69-1.14, for all-cause pneumonia; and 1.00, 95% CI 0.87-1.14, for all-cause mortality).
  

Conclusion: Pneumococcal vaccination does not appear to be effective in preventing pneumonia, even in populations for whom the vaccine is currently recommended.


Reference: Click to get abstract

Huss A; Scott P; Stuck AE; Trotter C; Egger M. Efficacy of pneumococcal vaccination in adults: a meta-analysis. CMAJ 2009; 180(1): 48-58