Streptococcus pneumoniae capsular polysaccharide antigens (21 serotypes) (PnPS-21)

Streptococcus pneumoniae capsular polysaccharide antigens are complex carbohydrate structures that encapsulate the bacterium, serving as its primary defense against the host immune system. These polysaccharides inhibit opsonophagocytosis, allowing the pathogen to survive and disseminate within the host (NIH, 2023). The specific 21 serotypes targeted here (3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20, 22F, 23A, 23B, 24F, 31, 33F, and 35B) represent the strains most frequently associated with invasive pneumococcal disease in adults (FDA, 2024). In therapeutic applications, these polysaccharides are typically conjugated to a carrier protein, such as CRM197, to enhance immunogenicity. This conjugation converts the T-cell independent polysaccharide into a T-cell dependent antigen, inducing robust antibody production and immunological memory (Merck, 2024). Vaccination effectively primes the immune system to recognize and neutralize these specific bacterial strains, preventing severe infections such as pneumonia, meningitis, and sepsis.

Other names

Pneumococcal capsular polysaccharidesS. pneumoniae CPSV116 antigens21-valent pneumococcal vaccine antigens

Active immunization; induction of opsonophagocytic antibodies against specific bacterial serotypes.