The purpose of this study is to evaluate that the vaccine produced with the new process and administered as a single dose is at least as good as the existing Mencevax™ ACWY vaccine in terms of immunogenicity, safety and reactogenicity, in healthy subjects aged 2-30 years.

"Randomized study with four groups to receive one of the following vaccination regimens: - One of the 3 lots of GSK Biologicals' Mencevax™ ACWY vaccine manufactured by the new process (3 different groups) - GSK Biologicals' already existing Mencevax™ ACWY

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.

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.