TABLE 3.

Serogroup-specific IgG concentrations for serogroups A, C, Y, and W135 by age group before and 1 month following vaccination with tetravalent polysaccharide vaccine

Serogroup	Age group (mo)	Prevaccination		1 mo postvaccination
		No.	GMC (μg/ml) (95% confidence interval)	No.	GMC (μg/ml) (95% confidence interval)
A	6	43	2.4 (1.8-3.1)	44	4.1 (3.1-5.5)
	12	46	1.9 (1.4-2.5)	44	7.5 (5.2-11.0)
	18	49	2.9 (2.4-3.5)	49	9.5 (6.7-13.5)
	24	68	1.6 (1.2-2.1)	67	7.3 (4.9-10.8)
	36	78	2.6 (1.9-3.4)	77	10.9 (7.7-15.3)
	48	93	2.6 (2.1-3.2)	92	10.4 (7.8-13.8)
C	6	43	1.9 (1.4-2.6)	44	2.8 (2.3-3.4)
	12	46	1.9 (1.4-2.5)	46	3.4 (2.7-4.3)
	18	49	2.3 (1.8-2.9)	49	3.4 (2.7-4.3)
	24	68	1.7 (1.4-2.0)	67	3.0 (2.5-3.8)
	36	78	1.9 (1.6-2.3)	77	2.4 (1.8-3.2)
	48	92	2.0 (1.7-2.4)	91	3.4 (2.7-4.2)
W135	6	43	1.0 (0.7-1.3)	44	1.3 (1.0-1.6)
	12	46	0.9 (0.7-1.2)	46	1.7 (1.4-2.3)
	18	49	0.9 (0.7-1.1)	49	1.7 (1.4-2.1)
	24	68	0.7 (0.6-0.9)	68	1.6 (1.3-2.1)
	36	78	0.9 (0.8-1.1)	77	1.8 (1.3-2.3)
	48	93	0.9 (0.8-1.2)	93	2.2 (1.6-2.9)
Y	6	43	0.4 (0.2-0.5)	43	0.6 (0.5-0.8)
	12	46	0.3 (0.2-0.5)	46	0.7 (0.5-0.9)
	18	49	0.4 (0.3-0.5)	49	0.9 (0.7-1.1)
	24	68	0.3 (0.2-0.3)	66	1.1 (0.8-1.6)
	36	78	0.4 (0.3-0.4)	77	1.1 (0.8-1.6)
	48	93	0.4 (0.3-0.5)	92	2.0 (1.4-2.9)