Study to evaluate immunogenicity and safety of GSK Biologicals’ Herpes Zoster subunit (HZ/su) vaccine at 9 and 10 years after vaccine administration and assessment of re-vaccination with 2 additional doses at 10 years after initial vaccination, in healthy subjects aged 60 years of age(YOA) and older

Subjects who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the diary cards, return for follow-up visits, ability to have scheduled contacts to allow evaluation during the study). Or subjects with a caregiver who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the diary cards, vaccination visits, availability for follow-up contacts).

• Written informed consent obtained from the subject prior to performance of any study specific procedure.
• Previous participation in study ZOSTER-003 (NCT00434577), in group 50 µg gE / AS01B, and who completed the vaccination course (2 doses of HZ/su) in study ZOSTER-003 (NCT00434577).
• Subjects are expected to enter the study (or complete Visit 1) as of the time they turn 108 months after first vaccination of previous vaccination course with HZ/su and not later than 111 months.

Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine during the period starting 30 days before the first study visit (Day -29 to Day 0), or planned use during the study period.

• Use or anticipated use of immunosuppressants or immune-modifying drugs during the period starting six months prior to study start and during the whole study period. This includes chronic administration of corticosteroids (>14 consecutive days of prednisone at a dose of ≥20 mg/day [or equivalent]), long-acting immune-modifying agents (e.g., infliximab) or immunosuppressive/cytotoxic therapy (e.g., medications used during cancer chemotherapy, organ transplantation or to treat autoimmune disorders).
• Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease (e.g., malignancy, human immunodeficiency virus [HIV] infection).
• Administration or planned administration of a live vaccine in the period starting 30 days before the first dose of study vaccine and ending 30 days after the last dose of study vaccine, or, administration or planned administration of a non-replicating vaccine* within 8 days prior to or within 14 days after either dose of study vaccine. E.g., inactivated and subunit vaccines, including inactivated and subunit influenza vaccines and pneumococcal conjugate vaccines.
• Previous vaccination against HZ since initial vaccination in Zoster-003.
• Administration of immunoglobulins and/or any blood products during the period starting 3 months before the study start, or planned administration during the study period.
• History of previous HZ.