Study in Toddlers to Demonstrate Non-inferiority of GSK Biologicals' Hib-MenC & to Evaluate Persistence up to 5 Years.

Inclusion Criteria: Primary phase: * Subjects whom the investigator believes that their parents/guardians can and will comply with the requirements of the protocol. * A male or female between, and including, 12 and 18 months of age at the time of vaccination. * Written informed consent obtained from the parent or guardian of the subject. * Free of obvious health problems as established by medical history and clinical examination before entering into the study. * Previously completed routine childhood vaccinations to the best of his/her parents'/guardians knowledge. * Having completed primary vaccination with two doses of Haemophilus influenzae type b outer membrane protein (Hib-OMP) containing vaccine OR three doses of diphtheria, tetanus, acellular pertussis and Haemophilus influenzae type b (DTPa/Hib) containing vaccine at least 6 months before the study start. Long-term persistence phase: \- Having participated in the vaccination study 106445 Exclusion Criteria: For the primary vaccination phase: * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period. * Chronic administration (defined as more than 14 days) or planned administration of immuno-suppressants or other immune-modifying drugs within six months prior to vaccination. * Planned administration/administration of a vaccine not foreseen by the protocol during the perio…