• Vaccine response to MenC [ Time Frame: One month after vaccination ]
  

• Meningococcal rSBA titres [ Time Frame: Prior to and one month after vaccination ]
  
• Anti-meningococcal polysaccharide concentrations [ Time Frame: Prior to and one month after vaccination ]
  
• Occurrence of solicited local and general symptoms [ Time Frame: During the 4-day follow-up period after vaccination ]
  
• Occurrence of unsolicited symptoms [ Time Frame: Up to one month after vaccination ]
  
• Occurrence of SAEs [ Time Frame: Up to six months after vaccination ]
  
• Occurrence of specific AEs of rash, new onset of chronic illness(es) and conditions prompting emergency room visits' [ Time Frame: Up to six months after vaccination ]
  

The study has 2 study groups. One group will receive one dose of GSK Biologicals' vaccine GSK 134612 and the other group will receive one dose of licensed MenC-CRM197 vaccine. All subjects will have 2 blood samples taken: just before vaccination and one month after vaccination.

Inclusion Criteria:

• Subjects whose parents/guardians, the investigator believes can and will comply with the requirements of the protocol.
• A male or female between, and including, 2 and 10 years of age at the time of the vaccination.
• Written informed consent obtained from the parent(s) 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.

Exclusion Criteria:

• Use of any investigational or non-registered product (drug or vaccine) other than the study vaccines within 30 days preceding the study vaccine dose, or planned use during the study period.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the vaccine dose..
• Administration of a vaccine not foreseen by the study protocol during the period starting from one month before the dose of the study vaccine and ending 30 days after.
• Concurrently participating in another clinical study or planned participation 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 product.
• Previous vaccination with meningococcal polysaccharide vaccine of serogroup A, C W-135 and/or Y (for subjects below 6 years) or within the last five years (for subjects 6 years old and above).
• Previous vaccination with meningococcal polysaccharide conjugate vaccine serogroups A, C, W-135 and/or Y.
• History of meningococcal disease.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection, based on medical history and physical examination.
• A family history of congenital or hereditary immunodeficiency, until the immune competence of the potential vaccine recipient is demonstrated.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
• Major congenital defects or serious chronic illness.
• History of any neurologic disorders or seizures.
• Acute disease at the time of enrolment
• Administration of immunoglobulins and/or any blood products within the three months preceding the study vaccine dose or planned administration during the study period.

Exclusion criteria for specified regions in France

• Subjects in contact with somebody suffering from an invasive infection with meningococcal serogroups A, C, Y or W-135, or
• Subjects living in a geographic area in France where local outbreak with meningococcal serogroup C has occurred and would thus be likely to participate in a vaccination campaign against meningococcal serogroup C.