Pneumococcal capsular polysaccharides (13 serotypes) (PCV13 antigens)

Pneumococcal capsular polysaccharides are complex carbohydrate polymers that form the outermost protective layer of the bacterium Streptococcus pneumoniae (StatPearls, 2023). These polysaccharides are essential virulence factors that enable the pathogen to evade the host's immune system by inhibiting opsonization and phagocytosis (PubMed, PMID: 25833247). The 13 specific serotypes included in this target group (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) were selected based on their historical prevalence in causing invasive pneumococcal disease (CDC, 2022). In therapeutic applications, these polysaccharides are conjugated to a carrier protein, such as CRM197, to enhance their immunogenicity (FDA, Prevnar 13 Package Insert). This conjugation transforms the immune response from T-cell independent to T-cell dependent, leading to the development of high-affinity antibodies and immunological memory (PubMed, PMID: 21945147). By targeting these specific polysaccharides, vaccines significantly reduce the incidence of pneumonia, meningitis, and bacteremia caused by these strains.

Other names

Streptococcus pneumoniae capsular polysaccharidesPneumococcal antigens13-valent pneumococcal conjugate vaccine antigensPneumococcal polysaccharide antigens

Induction of active immunity through the production of serotype-specific antibodies that facilitate opsonophagocytosis and killing of Streptococcus pneumoniae (FDA, Prevnar 13 Package Insert; StatPearls, 2023).