Streptococcus pneumoniae capsular polysaccharides (24 serotypes) (PnPS-24)

Streptococcus pneumoniae capsular polysaccharides are complex carbohydrate polymers that form the outermost layer of the bacterium, serving as a primary virulence factor by protecting the pathogen from host phagocytosis and complement-mediated killing. There are over 100 known serotypes of S. pneumoniae, distinguished by the unique chemical structure of these polysaccharides, which determine the organism's antigenicity and invasiveness. In the context of a 24-valent vaccine target, these polysaccharides represent a specific set of antigens selected based on their prevalence in causing invasive pneumococcal disease (IPD) and antibiotic resistance. As therapeutic targets, these polysaccharides are utilized in conjugate vaccines where they are chemically linked to carrier proteins to enhance immunogenicity, particularly in infants and the elderly. By introducing these purified polysaccharides into the host, the immune system is primed to produce serotype-specific antibodies that opsonize the bacteria, allowing for efficient recognition and destruction by immune cells. This targeted approach is critical for preventing life-threatening infections such as pneumonia, meningitis, and sepsis. The 24-valent formulation specifically aims to provide broader coverage than existing 13, 15, or 20-valent vaccines by including additional emerging or high-burden serotypes.

Other names

Pneumococcal capsular polysaccharidesS. pneumoniae CPS24-valent pneumococcal polysaccharide antigensPneumococcal surface polysaccharides

Induction of serotype-specific humoral immunity and opsonophagocytic antibody responses to facilitate bacterial clearance.