Assess the Non-inferiority of GSK Biologicals' Mencevax™ ACWY (Manufactured by a New Process) vs Mencevax™ ACWY (the Already Existing Vaccine in the Market) When Given as a Single Dose to Subjects Aged 2-30 Yrs

Inclusion criteria: * Healthy male or female between 2 and 30 years of age at the time of vaccination. * If the subject is female, she must be of non-childbearing potential. If a subject is a female of childbearing potential, she must be abstinent or have used adequate contraceptive precautions for 30 days prior to vaccination, have a negative pregnancy test and must agree to continue such precautions for two months after vaccination. Exclusion criteria: * Use of any investigational or non-registered product (drug or vaccine) within 30 days preceding the administration of study vaccine, or planned use during the study period. * Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the vaccine dose. * Vaccination with a meningococcal vaccine within the last five years. * Planned administration/ administration of a vaccine not foreseen by the study protocol during the period starting from 15 days before vaccine administration and ending 30 days after. * History of or known exposure to meningococcal serogroup A, C, W135 or Y disease or contacts with subjects who had meningococcal disease. * Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination.