Table 2.

Known capsular polysaccharides among the four major bacterial meningeal pathogens.

Bacterial species	Known capsular types
Haemophilus influenzae	a b, c, d, e, f
Neisseria meningitidis	A, B, C, E, H, I, K, L, W, X, Y and Z
Streptococcus pneumoniae	1, 2, 3, 4, 5, 6A, 6B, 6Bii (6E), 6C, 6D, 6F, 6 G, 6H, 7F, 7A, 7B, 7C, 8, 9A, 9 L, 9 N, 9 V, 10F, 10A, 10B, 10C, 11F, 11A, 11B, 11C, 11D, 11E, 12F, 12A, 12B, 13, 14, 15F, 15A, 15B/C, 16F, 16A, 17F, 17A, 18F, 18A, 18B, 18C, 19F, 19A, 19B, 19C, 20A, 20B, 21, 22F, 22A, 23F, 23A, 23B, 24F, 24A, 24B, 25F, 25A, 27, 28F, 28A, 29, 31, 32F, 32A, 33F, 33A, 33B, 33C, 33D, 33E, 34, 35F, 35A, 35B, 35C, 36, 37, 38, 39, 40, 41F, 41A, 42, 43, 44, 45, 46, 47F, 47A, 48
Streptococcus agalactiae	Ia, Ib, II, III, IV, V, VI, VII, VIII, IX