Safety Study of Tritanrix-HepB/Hib-MenAC, Tritanrix-HepB/Hiberix, and Mencevax ACWY Vaccines in Children

Inclusion Criteria: * Written informed consent obtained from the parent or guardian of a healthy male or female child between, and including 15 and 18 months age (Philippines)/ 15 and 24 months age (Thailand) at the time of vaccination and who have previously received a 3-dose primary vaccination in the studies DTPwHB/HibMenAC-TT-004 (CPMS No. 759346/004) or DTPW-HBV=HIB-MENAC-TT-013 (eTrack No. 100791). Exclusion Criteria: * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine within 30 days preceding the vaccination, or planned use during the study period. * Chronic administration (\> than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to vaccination. * Planned administration/administration of a vaccine not foreseen by the study protocol within 30 days of vaccination. Note: Oral poliovirus vaccine can be given concomitantly. * Booster vaccination against diphtheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b (Hib) and/or meningococcal serogroups A and C disease, after the date of the study conclusion visit of the primary vaccination study.