Study of Immunological Memory Induced in Children by a Full 4 Dose Vaccination Schedule of 11 Valent Pneumococcal Conjugate Vaccine by Giving 1 Dose of Aventis Pasteur's 23-valent Pneumococcal Polysaccharide Vaccine (Pneumo 23)

Phase III Multicentric Open Study to Evaluate Immunological Memory Induced by 3-dose Primary Vaccination Followed by Booster Dose of GSK Biologicals' 11-valent Conjugate Pneumococcal Vaccine Compared to Unprimed Subjects by Giving 1 Dose of Aventis Pasteur's Pneumo 23

Evaluate the immunological memory induced by 4 doses of GSK Biologicals' 11valent pneumococcal vaccine; study antibody persistence 30 months after the 4 dose vaccination with GSK Biologicals' 11-valent pneumococcal vaccine in Undeca-Pn-010 study.

Primed group: 50 subjects who previously received 4 doses of GSK Biologicals' 11Pn-PD vaccine will receive 1 dose of Pneumo 23 Unprimed group (Control): 50 subjects who received GSK Biologicals' Havrix™ vaccine will receive 1 dose of Pneumo 23

Inclusion criteria: Male or female who participated in Undeca-Pn-010 study, were part of the blood subset and received 4 doses of GSK Biologicals' 11Pn-PD vaccine, or Havrix vaccine. Exclusion criteria: Use of any investigational or non-registered drug or vaccine other than the study vaccine within 30 days preceeding the first dose of study vaccine, or planned use during the study period. Administration of any additional pneumococcal vaccine since study end of Undeca-Pn-010 (347414/010)