Streptococcus pneumoniae type 10a capsular polysaccharide antigen

Streptococcus pneumoniae type 10a capsular polysaccharide antigen is a highly purified carbohydrate antigen derived from the capsule of *Streptococcus pneumoniae* serotype 10A. It is used as a component in pneumococcal vaccines for active immunization against diseases caused by this serotype, such as pneumococcal pneumonia and bacteremia. The capsular polysaccharide forms the dominant surface structure of *S. pneumoniae* and acts as a major virulence factor, protecting the bacterium from phagocytosis by host immune cells. Immunity induced by these antigens is strictly serotype-specific. Vaccines containing this antigen are administered via intramuscular or subcutaneous injection and induce actively acquired immunity through induction of anti-capsular antibodies that promote opsonophagocytosis and clearance of the bacteria. As with other S. pneumoniae capsules, its biosynthesis involves a dedicated gene cluster (cps locus), which encodes enzymes responsible for assembly and export of the specific polysaccharide structure on the bacterial surface. Capsular polysaccharides are essential targets for vaccine development because they mediate both virulence and immunogenicity. Widespread use of vaccines targeting multiple capsular types has significantly reduced disease burden but also led to shifts in circulating serotypes.

Other names

Pneumococcal capsular polysaccharide type 10A vaccinePNEUMOCOCCAL POLYSACCHARIDE SEROTYPE 10A

The vaccine induces an immune response specifically against S. pneumoniae expressing the type 10A capsule. Antibodies generated bind to the capsule, promoting opsonization and subsequent phagocytosis/destruction by immune cells.