The 20-valent pneumococcal conjugate vaccine (PCV20) contains 20 purified capsular polysaccharides of S pneumoniae (1, 3, 4, 5, 6A, 6 B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F).