Figure 3.
Immunogenic effects of pneumococcal vaccines.
Notes: Pneumococcal polysaccharide vaccines contain serotype-specific polysaccharide antigens only and induce T-cell-independent antibody production from B cells. These responses tend to wane over time. Pneumococcal conjugate vaccines contain serotype-specific polysaccharide antigens covalently linked to a carrier protein. These vaccines induce T-cell-dependent antibody production from B cells and improve immune memory, allowing antipneumococcal immunoresponses to be generated long after vaccination. Based on data from Clutterbuck et al,41 de Roux et al,40 Pollard et al,42 and Siegrist.43