Streptococcus pneumoniae type 4 capsular polysaccharide diphtheria CRM197 protein conjugate antigen

Streptococcus pneumoniae type 4 capsular polysaccharide diphtheria CRM197 protein conjugate antigen is a component of pneumococcal conjugate vaccines. It consists of the purified capsular polysaccharide from Streptococcus pneumoniae serotype 4 chemically linked (conjugated) to the nontoxic mutant diphtheria toxin carrier protein CRM197. This glycoconjugation enhances immunogenicity by inducing a T-cell dependent immune response and promoting immunological memory, especially in infants and young children who respond poorly to plain polysaccharides. The mechanism of action involves stimulating the production of opsonizing antibodies that facilitate phagocytosis and clearance of S. pneumoniae bacteria expressing serotype 4 capsule[1][3][5]. These antigens are included in multivalent vaccines such as Prevnar (PCV7), Prevnar 13 (PCV13), and newer formulations like Prevnar 20, which protect against multiple pneumococcal serotypes[1][5]. The primary indication is prevention of invasive pneumococcal disease caused by S. pneumoniae in infants, children, adults, and elderly populations[1][2][3].

Brand names

PrevnarPrevnar 13Prevnar13Prevnar-13Prevnar 20Prevnar20Prevnar-20Vaxneuvance

Other names

Streptococcus pneumoniae serotype 4 capsular antigen diphtheria CRM197 protein conjugate vaccine