[Chronic obstructive pulmonary disease (COPD)].

s were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, fulltext articles were obtained. Articles with an unknown eligibility were reviewed with a second clinical epidemiologist and then a group of epidemiologists until consensus was established. Data extraction was carried out by the author. Inclusion Criteria  studies comparing clinical efficacy of the influenza vaccine or pneumococcal vaccine with no vaccine or placebo;  RCTs published between January 1, 2000 and January 31, 2011;  studies including patients with COPD only ;  studies investigating the efficacy of the types of vaccines approved by Health Canada;  English language studies. Exclusion Criteria  non-RCTs;  studies investigating vaccines for other diseases;  studies comparing different variations of vaccines;  studies in which patients received 2 or more types of vaccines;  studies comparing different routes of administering vaccines;  studies not reporting clinical efficacy of the vaccine or reporting immune response only;  studies investigating the efficacy of vaccines not approved by Health Canada. Outcomes of Interest Primary Outcomes Influenza vaccination: Episodes of acute respiratory illness due to influenza virus.