Study to Evaluate Persistence of Antibodies After Vaccination With Meningococcal Vaccine GSK134612

Subjects were previously vaccinated at 12 to 23 months of age. This extension study starts 24 months after vaccination and the subjects who were vaccinated in the primary study will be enrolled in this extension phase. No new subjects will be enrolled.

This study will assess the long-term protection offered by the new meningococcal vaccine GSK 134612 compared to Meningitec™ up to 4 years after vaccination of toddlers. Subjects were previously vaccinated at 12 to 23 months of age with GSK Biologicals' meningococcal vaccine GSK 134612 or Meningitec™. All subjects received at least one dose of Priorix-Tetra™. This extension phase starts 24 months after vaccination and the subjects who were vaccinated in the primary study will be enrolled in this extension study. No new subjects will be enrolled. The subjects will have a blood sample taken at 24, 36 and 48 months after primary vaccination.

At Year 4 subjects will be boosted with the same meningococcal vaccine as given in the primary study, i.e. either the new meningococcal vaccine GSK 134612 or Meningitec™. Blood samples will be taken 1 and 12 months after the booster vaccination.

Eligibility Criteria:
Inclusion Criteria:

* Subjects who the investigator believes that their parent(s)/guardian(s) can and will comply with the requirements of the protocol should be enrolled in the study.
* Written informed consent obtained from the parent(s) or guardian(s) of the subject.
* Healthy subjects as established by medical history and clinical examination before entering into the study.
* A male or female having completed the primary study 109670 and who was primed with the investigational or Meningitec™ vaccines.

Exclusion Criteria:

Exclusion criteria for persistence study entry (i.e. Month 24, 36 or 48):

* Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the subject's first visit.
* History of meningococcal disease.
* Administration of a meningococcal polysaccharide or a meningococcal polysaccharide conjugate vaccine outside of study 109670.
* Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history.
* Administration of immunoglobulins and/or blood products within the three months preceding the subjects first visit.
* Concurrently participating in another clinical study, within 30 days of study entry, in which the subject has been or will be exposed to an investigational or a non-investigational product (pharmaceutical product or device).
* Bleeding disorders, such as thrombocytopenia, or subjects on anti-coagulant therapy.

Additional exclusion criteria for booster vaccination (to be checked at Month 48):

* Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the booster vaccination.
* History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
* Hypersensitivity to any vaccine containing diphtheria toxoid or non-toxic diphtheria toxin protein and/or tetanus toxoid.
* History of hypersensitivity after previous administration of Meningitec or the investigational vaccines in study 109670.
* Hypersensitivity to latex.
* Planned administration/ administration of a vaccine not foreseen by the protocol within one month before and 30 days after the booster dose.
* Previous vaccination with any component of the vaccines within the last month.
* History of any neurological disorder or seizures (one episode of febrile convulsion does not constitute an exclusion criteria).
* Major congenital defects or serious chronic illness.
* Acute disease at the time of vaccination.