Pneumococcal capsular polysaccharide antigens (20 serotypes) (CPS)

Pneumococcal capsular polysaccharide antigens are the primary virulence factors of Streptococcus pneumoniae, forming a protective outer layer that prevents phagocytosis by the host immune system (CDC, 2023). These antigens are chemically distinct carbohydrates that define the various serotypes of the bacteria, with the 20-valent formulation targeting the most prevalent and invasive strains (FDA, 2021). The 20 serotypes included are 1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F (Pfizer, 2021). In therapeutic applications, specifically conjugate vaccines, these polysaccharides are linked to a carrier protein like CRM197 to enhance immunogenicity (StatPearls, 2023). This conjugation allows the immune system to mount a T-cell dependent response, leading to the production of high-affinity IgG antibodies and the establishment of immunological memory (PubMed, 2022). By targeting these specific polysaccharides, vaccines effectively prevent invasive pneumococcal diseases such as meningitis and bacteremia, as well as mucosal infections like pneumonia (NIH, 2023). The interaction between the vaccine-induced antibodies and the capsular antigens facilitates opsonophagocytosis, the primary mechanism for clearing pneumococcal infections (PubMed, 2021).

Other names

Streptococcus pneumoniae capsular polysaccharidesPneumococcal CPSPCV20 antigens20-valent pneumococcal conjugate vaccine antigens

Induction of serotype-specific opsonophagocytic antibodies that facilitate bacterial clearance by the immune system.