Study to evaluate efficacy, safety and immunogenicity of GlaxoSmithKline (GSK) Biologicals’ Herpes Zoster (HZ) vaccine GSK1437173A in adults aged 70 years and older

Subjects who the investigator believes will comply with the requirements of the protocol.

• Written informed consent obtained from the subject.
• A male or female aged 70 years or older at the time of the first vaccination.

Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the first dose of study vaccine, or planned use 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 product.
• Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease or immunosuppressive/cytotoxic therapy History of HZ.
• Previous vaccination against varicella or HZ.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine. Additionally, consider allergic reactions to other material or equipment related to study participation.
• Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study.
• Receipt of immunoglobulins and/or any blood products within the 90 days preceding the first dose of study vaccine or planned administration during the study period.
• Administration or planned administration of any other immunizations within 30 days before the first or second study vaccination or scheduled within 30 days after study vaccination. However, licensed non-replicating vaccines may be administered up to 8 days prior to each dose and/or at least 14 days after any dose of study vaccine.
• Any other condition that, in the opinion of the investigator, might interfere with the evaluations required by the study.
• Acute disease and/or fever at the time of enrolment.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose.