Immunogenicity, Reactogenicity and Safety of GlaxoSmithKline (GSK) Biologicals' MenACWY-TT Vaccine Administered 6 Years Post-MenC Primary Vaccination in Healthy Subjects Who Were 12-18 Months at Primary Vaccination

Inclusion Criteria: * Subjects' parent(s)/Legally Acceptable Representative(s) who, in the opinion of the investigator, can and will comply, with the requirements of the protocol. * A male or female between, and including, 84 and 95 months of age at the time of the booster vaccination. * Written informed consent obtained from the parent(s)/LAR(s) of the subject and written informed assent obtained from the subject in accordance with local laws and regulations. * Healthy subjects as established by medical history and history-directed physical examination before entering into the study. * Having completed the vaccination in the study \[Hib-MenC-TT-016 (106445)\] as per protocol. Exclusion Criteria: * Child in care. * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine within 30 days preceding the dose of study vaccine, or planned use during the study period. * Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the vaccine dose. For corticosteroids, this will mean prednisone ≥ 0.5 mg/kg/day, or equivalent. Inhaled and topical steroids are allowed. * Administration of a vaccine not foreseen by the study protocol within the period starting 30 days before and ending 30 days after the study vaccine dose, with the exception of a licensed inactivated influenza vaccine which can be administered at any time during the study according to the local recommendations. * Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational vaccine/product. * Previous vaccination with meningococcal vaccine except the meningococcal vaccination received in the Hib-MenC-TT-016 study. * History of meningococcal disease. * Any confirmed or suspected immunosuppressive or immunodeficient condition (congenital or secondary), including Human Immunodeficiency Virus (HIV)infection, based on medical history and physical examination (no laboratory testing required). * Family history of congenital or hereditary immunodeficiency. * History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccine, and history of serious allergic reaction (anaphylaxis) following the administration of vaccine(s). * Major congenital defects or serious chronic illness. * History of any neurological disorders or seizures, including GBS. History of a simple, single febrile seizure is permitted. * Acute disease and/or fever at the time of enrollment. * Fever is defined as temperature ≥ 37.5°C for oral, axillary or tympanic route, or ≥ 38.0°C for rectal route. The preferred route for recording temperature in this study will be oral. * Subjects with a minor illness (such as mild diarrhoea, mild upper respiratory infection) without fever may be enrolled at the discretion of the investigator. * Administration of immunoglobulins and/or any blood products within the 3 months preceding the study vaccination or planned administration during the booster vaccination phase of the study (i.e. between Visit 1 and Visit 2) and within 3 months preceding the blood sampling at Visit 3. The following criteria should be checked for the long-term persistence phase at two years after booster vaccination (Visit 3): In case an exclusion criterion becomes applicable, the subject will not enter the long-term follow-up and the reason will be documented. * Previous administration of a meningococcal vaccine with the exception of the meningococcal vaccination given in the primary study and the booster vaccination in this particular study. * History of meningococcal disease.