Please assess the completion status of the following clinical trial:

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

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: TRIPLE
- Phase: PHASE2
- Number of Arms: 4.0

Eligibility Criteria:
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.

- Gender: ALL
- Minimum Age: 50 Years
- Maximum Age: None
- Healthy Volunteers: t

Study Arms:
- GSK1437173A formulation 1 Group (Type: EXPERIMENTAL): Male or female subjects, 50 years of age or above, who received 2 doses of GSK1437173A (gE/ASO1B and gE/ASO1E) formulation 1 vaccine, administered intramuscularly in the upper deltoid region of the non-dominant arm on a 0, 2 month schedule.
- GSK1437173A formulation 2 Group (Type: EXPERIMENTAL): Male or female subjects, 50 years of age or above, who received 2 doses of GSK1437173A (gE/ASO1B and gE/ASO1E) GSK1437173A formulation 2 vaccine, administered intramuscularly in the upper deltoid region of the non-dominant arm on a 0, 2 month schedule.
- GSK1437173A formulation 3 Group (Type: EXPERIMENTAL): Male or female subjects, 50 years of age or above, who received 2 doses of GSK1437173A (gE/ASO1B and gE/ASO1E) formulation 3 vaccine, administered intramuscularly in the upper deltoid region of the non-dominant arm on a 0, 2 month schedule.
- Control Group (Type: PLACEBO_COMPARATOR): Male or female subjects, 50 years of age or above, who received 2 doses of saline solution (placebo), administered intramuscularly in the upper deltoid region of the non-dominant arm on a 0, 2 month schedule.

Based on this trial design, predict the completion outcome and termination type (if applicable).

Answer: outcome: complete