Injectable vaccines for preventing pneumococcal infection in patients with chronic obstructive pulmonary disease

As chronic obstructive pulmonary disease (COPD) progresses, exacerbations can occur with increasing frequency. One goal of therapy is to prevent these exacerbations, thereby reducing morbidity and associated healthcare costs. Pneumococcal vaccinations are one strategy for reducing the risk of infective exacerbations. To determine the safety and efficacy of pneumococcal vaccination in COPD. The primary outcomes assessed were episodes of pneumonia and acute exacerbations. Secondary outcomes of interest included hospital admissions, adverse events related to treatment, disability, change in lung function, mortality, and cost effectiveness. We searched the Cochrane Airways Group COPD trials register and the databases CENTRAL, MEDLINE and EMBASE using pre-specified terms. The latest searches were performed in March 2010. Randomised controlled trials assessing the effects of injectable pneumococcal vaccine in people with COPD were included. Two review authors independently extracted data and three review authors independently assessed trial quality. Seven studies were identified that met the inclusion criteria for this review and were included in the 2010 review update. Two older trials used a 14-valent vaccine and five more recent trials used a 23-valent injectable vaccine.In six studies involving 1372 people, the reduction in likelihood of developing pneumonia with pneumococcal vaccination compared to control did not achieve statistical significance, the odds ratio (OR) was 0.72 (95% confidence interval (CI) 0.51 to 1.01), with moderate heterogeneity present between studies. The reduction in likelihood of acute exacerbations of COPD from two studies involving 216 people was not statistically significant (Peto OR 0.58; 95% CI 0.30 to 1.13).Of the secondary outcomes for which data were available there was no statistically significant effect for reduction in hospital admissions (two studies) or emergency department visits (one study). There was no significant reduction in pooled results from three studies involving 888 people for odds of all-cause mortality for periods up to 48 months post-vaccination (OR 0.94; 95% CI 0.67 to 1.33), or for death from cardiorespiratory causes (OR 1.07; 95% CI 0.69 to 1.66). The limited evidence from randomised controlled trials (RCTs) included in this review suggests that, while it is possible that injectable polyvalent pneumococcal vaccines may provide some protection against morbidity in persons with COPD, no significant effect on any of the outcomes was shown. Further large RCTs in this population would be needed to confirm effectiveness of the vaccine suggested by results from longitudinal studies.