Vaccines for preventing pneumococcal infection in adults. Summary of the evidence and implications for public health programmes

An update of a Cochrane systematic review summarised the evidence for the efficacy of pneumococcal polysaccharide vaccines (PPVs) from randomized controlled trials (RCTs) or quasi-RCTs that compared PPV with placebo, control vaccines or no intervention; and from non-RCTs that assessed pneumococcal vaccine effectiveness against sterile site, culture confirmed IPD where the trial design allowed for the control of important confounding factors (case-control and cohort studies). Of 25 included studies, 18 were RCTs including 64,852 participants and seven were non-RCTs - five case-control studies and two cohort studies including 62,294 participants; the non-RCTs contributing outcomes for culture-confirmed invasive pneumococcal disease (IPD) only.The review found consistently strong evidence that the vaccine is effective in preventing the rarer outcome of invasive pneumococcal disease. Evidence from the included studies indicates vaccination might not afford as much protection in adults with chronic illness as it does for healthy adults. The available evidence did not demonstrate that pneumococcal polysaccharide vaccines prevent pneumonia (of all causes) or mortality in adults. This review did not consider adverse events.