Table 3.

Post-immunization serotype-specific antibody concentrations: comparison between responders and non responders according to the OA results.

	Responders* (groups I and II; n = 81)	Non-responders (groups III and IV; n = 12)	P-value
Serotype 14	3·40 (4)	0·95 (3)	0·006
Serotype 19F	2·89 (4)	0·72 (2)	< 0·001
Serotype 23F	0·94 (4)	0·20 (2)	0·001

Results are expressed as geometric means in µg/ml and standard deviation in brackets.

^*Responders = ratio ≥2 and post-immunization level ≥11 AU/ml.