Study to Evaluate Immunogenicity and Safety Study of GSK Biologicals' Herpes Zoster (HZ) Vaccine GSK1437173A When Co-administered With Pneumovax 23™ in Adults Aged 50 Years and Older

The purpose of this study is to assess the immunogenicity, reactogenicity and safety of the GSK Biologicals HZ/su candidate vaccine when its first dose is co-administered with Pneumovax 23™ vaccine in adults aged 50 years or older.The impact of HZ/su vaccine on Pneumovax 23™ vaccine immune response will also be evaluated.


Eligibility Criteria:
Inclusion Criteria:

* Subjects who, in the opinion of the investigator, can and will comply with the requirements of the protocol.
* A male or female aged 50 years or older at the time of the first vaccination with the study vaccine(s).
* Written informed consent obtained from the subject.
* Female subjects of non-childbearing potential may be enrolled in the study.

  * Non-childbearing potential is defined as pre-menarche, current tubal ligation, hysterectomy, ovariectomy or post-menopause.
* Female subjects of childbearing potential may be enrolled in the study, if the subject:

  * has practiced adequate contraception for 30 days prior to vaccination, and
  * has a negative pregnancy test on the day of vaccination, and
  * has agreed to continue adequate contraception during the entire treatment period and for 2 months after completion of the vaccination series.

Exclusion Criteria:

* Use of any investigational or non-registered product other than the study vaccines within 30 days preceding the first dose of study vaccine, or planned use during the study period.
* Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. A prednisone dose of \< 20 mg/day is allowed. Inhaled, topical and intra-articular corticosteroids are allowed.
* Administration or planned administration of a vaccine not foreseen by the study protocol within the period starting 30 days before the first dose of study vaccine(s) and ending 30 days after the last dose of study vaccine. This includes any type of vaccine such as live, inactivated and subunit vaccines.
* Administration of long-acting immune-modifying drugs within six months prior to the first vaccine dose or expected administration at any time during the study period.
* Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational vaccine/product.
* Previous vaccination against Varicella-zoster virus (VZV) or HZ and/or planned administration during the study of an HZ or VZV vaccine other than the study vaccine.
* History of HZ.
* History of documented pneumococcal infection within 5 previous years.
* Prior receipt of any pneumococcal vaccine or planned use of this vaccine during the study period, other than the study vaccine.
* Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease or immunosuppressive/cytotoxic therapy .
* History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccines.
* Acute disease and/or fever at the time of enrolment.

  * Fever is defined as temperature ≥ 37.5°C /99.5°F by oral route. The preferred route for recording temperature in this study will be oral.
  * Subjects with a minor illness (such as mild diarrhea, mild upper respiratory infection) without fever may, be enrolled at the discretion of the investigator.
* Administration of immunoglobulins and/or any blood products within the 3 months preceding the first dose of study vaccine or planned administration during the study period.
* Pregnant or lactating female.
* Female planning to become pregnant or planning to discontinue contraceptive precautions before 2 months after the last dose of study vaccine.
* Any persons with cerebrospinal fluid (CSF) leaks, cochlear implants, chronic renal failure, nephrotic syndrome, and functional or anatomic asplenia.
* Any condition which, in the opinion of the investigator, prevents the subject from participating in the study.
* Any condition which, in the judgment of the investigator, would make intramuscular (IM) injection unsafe.