Immunogenicity and Safety of Meningococcal Vaccine GSK134612 vs. Menactra® in Healthy Adolescent/Adults Aged 10-25 Years.

Subjects 11-25 years of age will be randomized to receive either the meningococcal vaccine
GSK134612 or Menactra®. An additional non-randomized group of subjects aged 10 years (< 11
years of age) will be enrolled to receive meningococcal vaccine GSK134612 only (At the time
the study begun, Menactra® was only licensed in the United States for individuals above 11
years of age and therefore could not be used as a control vaccine in subjects less than 11
years old).

This study will be single-blind for the subjects 11 to 25 years of age and open for the
subjects 10 to < 11 years of age.

Inclusion Criteria:

- Subjects whom the investigator believes can and will comply with the requirements of
the protocol.

- A male or female between, and including, 10 and 25 years of age (has not attained
his/her 26th birthday) at the time of the vaccination.

- Written informed consent obtained from parents/guardian of the subject and written
informed assent obtained from the subject if the subject is less than 18 years of age,
or written informed consent obtained from the subject if the subject has achieved the
18th birthday.

- Healthy subjects as established by medical history and clinical examination before
entering into the study.

- If the subject is female, she must be of non-childbearing potential, or if she is of
childbearing potential, she must practice adequate contraception (including
abstinence) for 30 days prior to vaccination, have a negative pregnancy test and
continue such precautions for 2 months after vaccination.

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 or conjugate vaccine of
serogroup A, C W-135, and/or Y.

- Previous vaccination with tetanus and diphtheria toxoids within the last month (i.e.,
Tdap, Td, and TT-containing vaccine within the last month).

- History of meningococcal disease due to serogroup A, C, W-135, or Y.

- Any confirmed or suspected immunosuppressive or immunodeficient condition (congenital
or secondary), including human immunodeficiency virus (HIV) infection, based on
medical history and physical examination (no laboratory testing is required).

- 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.

- Hypersensitivity to latex.

- Major congenital defects or serious chronic illness.

- History of any neurologic disorders or seizures.

- Previous history of Guillain-Barré Syndrome.

- Bleeding disorders, such as hemophilia or thrombocytopenia, or subjects on
anti-coagulant therapy.

- Acute disease at the time of enrollment.

- 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.