Streptococcus pneumoniae type 33F capsular polysaccharide diphtheria CRM197 protein conjugate antigen

Streptococcus pneumoniae type 33F capsular polysaccharide diphtheria CRM197 protein conjugate antigen is a sterile vaccine that contains saccharides of the capsular antigens of Streptococcus pneumoniae serotype 33F individually conjugated to the CRM197 protein, a nontoxic variant of diphtheria toxin isolated from cultures of Corynebacterium diphtheriae strain C7 (β197). It is contained in the vaccine under the market name Prevnar that contains the saccharides for serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F for intramuscular injection. The saccharides in the vaccine are prepared from purified polysaccharides that are chemically activated then conjugated to the protein carrier CRM197 to form the glycoconjugate.