Immunogenicity and Safety Study of GSK Biologicals' Herpes Zoster Vaccine With Various Formulations in Adults >= 50 Years

Inclusion Criteria:

- A male or female 50 years of age or above at the time of the first vaccination;

- Written informed consent obtained from the subject;

- Subjects who the investigator believes that they can and will comply with the
requirements of the protocol should be enrolled in 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 for 30 days prior to
vaccination, have a negative pregnancy test and continue such precautions for 2 months
after completion of the vaccination series.

Exclusion Criteria:

- Use of any investigational or non-registered product (drug or vaccine) other than the
study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned
use during the study period;

- Chronic administration (defined as more than 14 consecutive days) of
immunosuppressants or other immune-modifying drugs within three months prior to the
first vaccine dose.

- Planned administration/ administration of a vaccine not foreseen by the study protocol
within one month before the first study vaccination or scheduled within 30 days after
study vaccination;

- Previous vaccination against HZ;

- Previous vaccination against varicella;

- History of HZ;

- History of allergic disease or reactions likely to be exacerbated by any component of
the vaccine;

- Any confirmed or suspected immunosuppressive or immunodeficient condition resulting
from disease or immunosuppressive/cytotoxic therapy;

- Administration of immunoglobulins and/or any blood products within the 3 months
preceding the first injection of study vaccine or planned administration during the
study period;

- Acute disease at the time of enrolment.

- Any other condition that, in the opinion of the investigator, might interfere with the
evaluations required by the study;

- History of or current drug and/or alcohol abuse;

- Pregnant or lactating female;

- Female planning to become pregnant or planning to discontinue contraceptive
precautions if of childbearing potential.