Table 1.

Pre-immunization anti-pneumococcal antibody concentrations in different age groups according to the two assays.

	Age groups
	< 2 years	2–5 years	6–10 years	> 10 years
	n = 21	n = 96	n = 47	n = 12	Correlation
Serotype 14	0·63*	0·94	1·84	1·62	r = 0·305
	0·12–11·92	0·04–63·67	0·17–27·17	0·11–38·30	P < 0·001
Serotype 19F	0·64	1·33	1·47	2·92	r = 0·185
	0·12–7·06	0·09–13·73	0·16–71·3	0·32–38·4	P = 0·014
Serotype 23F	0·24	0·42	0·63	0·96	r = 0·264
	0·04–2·60	0·04–9·48	0·09–22·04	0·04–25	P < 0·001
Overall assay	3	5	9	12	r = 0·504
	< 3–9	< 3–120	< 3–95	3–62	P < 0·001

Pre-immunization anti-pneumococcal antibody concentrations were correlated significantly with the patient's ages for all serotypes and for the overall assay.

^*Values are geometric means and ranges in µg/ml for each serotype for the serotype-specific assay (SSA) and in AU/ml for the overall assay (OA).