Pneumococcal vaccination among adults with chronic respiratory diseases: a historical overview.

Streptococcus pneumoniae, the most common cause of community-acquired pneumonia, remains a major cause of morbidity and mortality worldwide. The presence of chronic respiratory illness is a major risk factor for pneumonia, and smoking (the most common cause of chronic obstructive pulmonary disease) is also an important risk factor for pneumonia and invasive pneumococcal disease. There are currently three established approaches to antipneumococcal vaccination: capsular polysaccharide pneumococcal vaccines (recommended for adults and some children at risk), protein-polysaccharide conjugate pneumococcal vaccines (classically recommended for infants and young children and currently under evaluation for adults aged 50 years or older for the prevention of invasive disease) and experimental protein-based pneumococcal vaccines (under investigation in animal models). Although patients with chronic respiratory diseases are commonly described as an at-risk population for pneumococcal infections, studies on pneumococcal vaccination efficacy in such patients are very limited and vaccination effectiveness remains controversial. This paper reviews available data on the efficacy and effectiveness of polysaccharide pneumococcal vaccination among adults with chronic respiratory diseases.