Prevnar 20, Pneumococcal 20-valent Conjugate Vaccine is a sterile suspension of saccharides of the capsular antigens of S. pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F, individually linked to non-toxic diphtheria CRM197 protein. Each serotype is grown in soy peptone broth. The individual polysaccharides are purified by a series of chemical and physical methods. The polysaccharides are chemically activated and then directly conjugated to the carrier protein CRM197, to form the glycoconjugate. CRM197 is a non-toxic variant of diphtheria toxin isolated from cultures of Corynebacterium diphtheriae strain C7 (β197) grown in a casamino acids and yeast extract-based medium or in a chemically-defined medium. CRM197 is purified by a series of chemical and physical methods. The individual glycoconjugates are purified by a series of chemical and physical methods and analyzed for saccharide to protein ratios, molecular size, free saccharide, and free protein.
The individual glycoconjugates are compounded to formulate Prevnar 20. Potency of the formulated vaccine is determined by quantification of each of the saccharide antigens and by the saccharide to protein ratios in the individual glycoconjugates. Each 0.5 mL dose of the vaccine is formulated to contain approximately 2.2 μg of each of S. pneumoniae serotypes 1, 3, 4, 5, 6A, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, 33F saccharides, 4.4 μg of 6B saccharides, 51 μg CRM197 carrier protein, 100 μg polysorbate 80, 295 μg succinate buffer, 4.4 mg sodium chloride, and 125 μg aluminum as aluminum phosphate adjuvant.