Streptococcus pneumoniae capsular polysaccharide–CRM197 protein conjugate

Streptococcus pneumoniae capsular polysaccharide–CRM197 protein conjugate consists of bacterial capsular polysaccharides (derived from major S. pneumoniae serotypes) covalently linked to CRM197, a non-toxic mutant form of diphtheria toxin used as a protein carrier to significantly increase immune recognition and antibody production, especially in children under two years old. This conjugation converts the otherwise poorly immunogenic polysaccharide antigens into effective, T cell-dependent vaccine components. These conjugates are the key antigens in approved pneumococcal conjugate vaccines such as Prevnar 13, Prevnar 20, and Vaxneuvance, which protect against invasive pneumococcal diseases by inducing robust, serotype-specific immune responses.

Other names

Pneumococcal capsular polysaccharide–CRM197 conjugatePneumococcal conjugate vaccine antigenInactivated pneumococcal vaccine antigenStreptococcus pneumoniae polysaccharide–diphtheria CRM197 protein conjugate antigen

Induces an adaptive immune response (including T-dependent antibody responses) to capsular polysaccharide antigens of S. pneumoniae when conjugated to the CRM197 protein carrier, enhancing immunogenicity particularly in young children. Prevents invasive disease by promoting opsonophagocytic antibodies targeting multiple S. pneumoniae serotypes.