ABSTRACT
Streptococcus pneumoniae expresses a number of molecules, aside from capsular polysaccharide, that are able elicit protection. Figure 1 is a cartoon of the pneumococcal surface depicting many different pneumococcal surface structures. All of the labeled structures, except the cell membrane and cell wall, are able to elicit protective responses. Data for some of these molecules are stronger than those of others. Although the data demonstrating protection by antibody to IgA1 protease are limited, its high sequence diversity suggests that the antibody to this protein has a protective effect in man [1].
