The effectiveness of pneumococcal polysaccharide vaccines in adults: a systematic review of observational studies and comparison with results from randomised controlled trials.
The use of pneumococcal polysaccharide vaccine has remained controversial since licensure, especially in the elderly. Observational studies form much of the evidence base. We conducted a systematic review of observational studies and compared results with those obtained from an earlier review of randomised controlled trials (RCTs). Estimates of protection against invasive disease from observational studies were consistent, homogenous and compatible with sparse information obtained from RCTs. Studies were of moderate quality. From 13 observational studies the estimate of vaccine efficacy against invasive disease was 53% (46-59%) compared with 38% (-4 to 63%) from nine RCTs. Estimates of protection against all-cause pneumonia were based on fewer, heterogeneous studies that were not consistent with the findings from RCTs for this outcome. From five studies combined efficacy was 32% (7-50%) compared with 3% (-16 to 19%) from 13 RCTs.
UCL Centre for Infectious Disease Epidemiology, Department of Primary Care and Population Science, Royal Free and University College Medical School, Royal Free Campus, London NW3 2PF, UK. s.conaty@pcps.ucl.ac.uk
Stephen
S
Conaty
Lorna
L
Watson
Jacqueline
J
Dinnes
Norman
N
Waugh
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D011008:Pneumococcal Infections / Q000276:immunology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000276:immunology* / Q000627:therapeutic use*; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic
D008070:Lipopolysaccharides; D022242:Pneumococcal Vaccines