Study in Adolescents/Adults to Evaluate Non-inferiority&Persistence up to 5 Years of GSK Bio MenACWY Conjugate Vaccine

Meningococcal disease is mostly caused by N. meningitidis of serogroups A, B, C, W-135, Y. Meningococcal polysaccharide-conjugate vaccines have the advantage to induce a T-cell dependant immune response while the existing polysaccharide vaccines induce a T-cell independent response, i.e. with no immune memory response. GSK Biologicals has developed a combined Men ACWY conjugate vaccine intended to protect against meningococcal disease due to serogroups A, C, W-135 and Y. In the vaccination phase of this study, the new MenACWY-TT conjugate vaccine will be evaluated in adolescents and adults using Mencevax™ ACWY as control. In the long-term follow-up phase (extension phase) of the study, the long-term protection offered by the new MenACWY-TT conjugate vaccine will be assessed up to five years after the vaccination in adolescents and adults using Mencevax™ ACWY as control. This protocol posting deals with objectives \& outcome measures of both the primary \& extension phases.

All subjects will have 7 blood samples taken: prior to and one month after vaccination and one, two, three, four and five years after vaccination. No new subjects will be enrolled in the extension phases of this Phase IIb study.

The Protocol Posting has been updated in order to comply with the FDA Amendment Act, September 2007.

Eligibility Criteria:
Inclusion Criteria:

* Subjects who the investigator believes that they and/or their parents/ legally acceptable representative can and will comply with the requirements of the protocol.
* A male or female between, and including, 11 and 55 years of age at the time of vaccination.
* Written informed consent obtained from the subject/ from the parent or legally acceptable representative 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 knowledge and/or his/her parents/legally acceptable representative's knowledge.
* If the subject is female, she must be of non-childbearing potential; or, if of childbearing potential, she must be abstinent or have used adequate contraceptive precautions for 30 days prior to vaccination, and must agree to continue such precautions for two months after completion of the vaccination series. Female subjects in childbearing potential who are not abstinent must have a negative pregnancy test.

Exclusion Criteria:

* Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the dose 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.
* Planned administration/ administration of a vaccine not foreseen by the study protocol within one month of the dose of vaccine(s).
* Previous vaccination with meningococcal polysaccharide vaccine of serogroup A, C W and/or Y within the last five previous years.
* Previous vaccination with meningococcal polysaccharide conjugate vaccine of serogroup A, C W and/or Y.
* History of meningococcal disease due to serogroup A, C, W or Y.
* Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection.
* A family history of congenital or hereditary immunodeficiency.
* 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.
* History of Guillain-Barré syndrome.
* Acute disease at the time of enrolment.
* Administration of immunoglobulins and/or any blood products within the three months preceding the first dose of study vaccine or planned administration during the study period.
* Pregnant or lactating female.
* History of chronic alcohol consumption and/or drug abuse.
* Female planning to become pregnant or planning to discontinue contraceptive precautions.

Specific criteria to be checked at each study visit for the long term follow-up:

* History of meningococcal serogroup A,C, W and Y disease.
* Administration of a meningococcal polysaccharide or a meningococcal polysaccharide conjugate vaccine not planned in the protocol.