streptococcus pneumoniae type 19a capsular polysaccharide diphtheria crm197 protein conjugate antigen

This is a vaccine component consisting of the purified capsular polysaccharide from Streptococcus pneumoniae serotype 19A, chemically conjugated to the nontoxic diphtheria toxin variant CRM197. The conjugation enhances immunogenicity by inducing a T-cell dependent immune response, leading to improved antibody production and immunological memory compared to unconjugated (polysaccharide-only) vaccines. This antigen is included as one of several serotypes in multivalent pneumococcal conjugate vaccines (such as PCV13, PCV15, and PCV20), which are used for active immunization against invasive diseases caused by Streptococcus pneumoniae—including pneumococcal pneumonia and bacteremia—especially in children and at-risk adults[1][2][3].

Other names

pneumococcal capsular polysaccharide type 19A vaccinestreptococcus pneumoniae type 19a capsular polysaccharide antigen