Streptococcus pneumoniae capsular polysaccharide (21 serotypes) (PnCP-21)

Streptococcus pneumoniae capsular polysaccharides are complex carbohydrate polymers that form the outermost layer of the bacterium, serving as its primary virulence factor by inhibiting host-mediated phagocytosis [3]. There are over 100 distinct serotypes, each defined by a unique polysaccharide structure that determines the pathogen's immunogenicity and prevalence [3]. The 21 specific serotypes (3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15B, 15C, 16F, 17F, 19A, 20, 22F, 23A, 23B, 24F, 31, 33F, and 35B) are the antigenic targets of the 21-valent conjugate vaccine Capvaxive, which is designed to provide broad protection against invasive pneumococcal disease in adults [1, 2]. These polysaccharides are chemically conjugated to a carrier protein, such as CRM197, to elicit a T-cell dependent immune response, which is necessary for the induction of high-affinity antibodies and immunological memory [4]. Vaccination with these epitopes stimulates the production of serotype-specific IgG antibodies and enhances opsonophagocytic activity, facilitating the clearance of the bacteria by the immune system [2]. This targeted approach addresses the epidemiological shift in pneumococcal disease by covering serotypes that are increasingly responsible for adult infections but were not included in previous vaccine formulations [1, 4].

Other names

Pneumococcal capsular polysaccharidePnCPCPSV116 antigensStreptococcus pneumoniae antigens