title: The Clinical Effectiveness of Pneumococcal Conjugate Vaccines: A Systematic Review and Meta-analysis of Randomized Controlled Trials.
abstract: BACKGROUND
  Streptococcus pneumoniae is responsible for approximately 1.6 million yearly deaths worldwide. An up-to-date evidence base on the effects of pneumococcal conjugate vaccines (PCVs) on infectious diseases and mortality in any population or setting regardless of age or health status is currently lacking.
  
  
  METHODS
  We systematically searched MEDLINE and EMBASE for pertinent randomized controlled trials (RCTs). Two reviewers independently screened 9498 titles/abstracts and 430 full-text papers for eligible trials. The outcomes of our meta-analysis were pooled using relative risks (RRs) with a random effects model or Peto's odds ratios (ORs) if event rates were :lt;1%.
  
  
  RESULTS
  21 RCTs comprising 361 612 individuals were included. PCVs reduced the risk for invasive pneumococcal disease (odds ratio [OR]: 0.43, 95% confidence interval [CI]: [0.36; 0.51]), all-cause acute otitis media (AOM) (RR: 0.93, 95% CI: [0.86; 1.00]), pneumococcal AOM (RR: 0.57, 95% CI: [0.39; 0.83]), allcause pneumonia (RR: 0.93, 95% CI: [0.89; 0.97]), and pneumococcal pneumonia (RR: 0.78, 95% CI: [0.62; 0.97]). We found no significant effect of PCVs on all-cause mortality (RR: 0.95, 95% CI: [0.88; 1.03]) or recurrent AOM (RR: 0.87, 95% CI: [0.72; 1.05]).
  
  
  CONCLUSIONS
  PCVs are associated with large risk reductions for pneumococcal infectious diseases, smaller risk reductions for infectious diseases from any cause, and no significant effect on all-cause mortality.
authors.affiliation: Basel Institute for Clinical Epidemiology and Biostatistics, Department of Clinical Research, University Hospital Basel, Switzerland, Department of Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada, Department of Endocrinology, Diabetology & Metabolism, University and Cantonal Hospital Aarau, Switzerland, Cantonal Hospital Aarau, Switzerland, Institute of Nuclear Medicine, University Hospital Bern, Bern, Switzerland.
authors.forename: Hannah
authors.initials: H
authors.lastname: Ewald
authors.forename: Matthias
authors.initials: M
authors.lastname: Briel
authors.forename: Danielle
authors.initials: D
authors.lastname: Vuichard
authors.forename: Veronika
authors.initials: V
authors.lastname: Kreutle
authors.forename: Andriy
authors.initials: A
authors.lastname: Zhydkov
authors.forename: Viktoria
authors.initials: V
authors.lastname: Gloy
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D038622:Internationality; D008297:Male; D032541:Mass Vaccination / Q000401:mortality* / Q000706:statistics & numerical data*; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000401:mortality* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D016896:Treatment Outcome; D018074:Vaccines, Conjugate / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate