Immunogenicity and Safety Study of GlaxoSmithKline (GSK) Biologicals' Combined Measles-mumps-rubella (MMR) Vaccine in Children in Their Second Year of Life

The purpose of this study is to evaluate end of shelf-life potency in terms of the immunogenicity and safety of GSK Biologicals' trivalent MMR vaccine, by comparing it to Merck \& Co., Inc.'s MMR vaccine, which is approved for use in the United States (US).

This trial is a Phase IIIA, randomized, observer-blind, controlled, multi-center, multi-country study with four parallel groups. This study will evaluate the immunogenicity and safety of GSK Biologicals' trivalent investigational MMR vaccine (referred to as Inv_MMR vaccine, throughout this document) in contrast to the US standard of care comparator vaccine (M-M-R II, Merck and Co., Inc., referred to as Com_MMR throughout this document) in children during their second year of life. The first dose of this two-dose study is designed to establish the end of shelf-life potency of Inv_MMR vaccine. The Inv_MMR vaccine will be given as one of two lots; one of a minimum potency, designated Inv_MMR_Min; and the other at a mid-range or medium potency designated Inv_MMR_Med to two groups. The second dose for both of these Inv_MMR groups will have a potency within the release range of the marketed vaccine. The Com_MMR vaccine will consist of two lots designated Com_MMR_L1 and Com_MMR_L2 and will be analyzed as pooled lots within the study. The first MMR vaccine dose will be co-administered with Varivax, Havrix and (in the US sub-cohort only) Prevnar 13 which are routinely administered to children of this age in the US.

Eligibility Criteria:
Inclusion Criteria:

* Male or female child between 12 and 15 months of age at the time of vaccination.
* The investigator believes that the parent(s) or Legally Acceptable Representative(s) (LAR(s)) of the child, can, and will comply with the requirements of the protocol.
* Written informed consent obtained from the parent(s)/LAR(s) of the child.
* Child is in stable health as determined by investigator's clinical examination and assessment of child's medical history.

For US children only:

• Child that previously received a 3-dose series of Prevnar 13 with last dose at least 60 days prior to study entry.

Exclusion Criteria:

* Child in care.
* Use of any investigational or non-registered product other than the study vaccine(s) during the period starting 30 days before the day of study vaccination or planned use during the entire study period.
* Concurrently participating in another clinical study, in which the child has been or will be exposed to an investigational or a non-investigational product. Chronic administration of immunosuppressants, or other immune-modifying drugs during the period starting 180 days prior to the first vaccine dose or any planned administration of immunosuppressive and immune-modifying drugs during the entire study.

  * Inhaled and topical steroids are allowed.
* Planned administration / administration of a vaccine not foreseen by the study protocol during the period starting 30 days prior to study vaccination at Visit 1 and ending at Visit 2 (or ending at Visit 3 for the US post-dose 2 sub-cohort). Please Note:

  * Inactivated influenza (Flu) vaccine and Haemophilus influenzae type b conjugate vaccine (Hib) vaccines may be given at any time during the study, including the day of study vaccination (Flu and Hib vaccines must be administered at a different location than the study vaccine/s).
  * Any age appropriate vaccine may be given starting at Visit 2 (or starting at Visit 3 for the US post-dose 2 sub-cohort), and anytime thereafter.
* Administration of immunoglobulins and/or any blood products during the period starting 180 days prior to study vaccination at Visit 1 or planned administration from the date of vaccination through the immunogenicity evaluation at Visit 2, or at Visit 3 for the US post-dose 2 sub-cohort.
* History of measles, mumps, rubella, varicella/zoster and/or hepatitis A diseases.
* Known exposure to measles, mumps, rubella and/or varicella/zoster during the period starting 30 days prior to the first study vaccination.
* Previous vaccination against measles, mumps, rubella, hepatitis A and/or varicella virus.
* Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination.
* A family history of congenital or hereditary immunodeficiency.
* History of allergic disease or reactions likely to be exacerbated by any component of the vaccines, including hypersensitivity to neomycin, latex or gelatin.
* Blood dyscrasias, leukemia, lymphomas of any type, or other malignant neoplasms affecting the bone marrow or lymphatic systems.
* Acute disease at the time of enrollment. Acute disease is defined as the presence of a moderate or severe illness with or without fever. Fever is defined as temperature ≥38°C/100.4°F by any age appropriate route. All vaccines can be administered to persons with a minor illness such as diarrhea, mild upper respiratory infection without fever.
* Active untreated tuberculosis based on medical history.
* Any other condition which, in the opinion of the Investigator, prevents the child from participating in the study.

For US children only:

• A child that previously received a fourth dose of any pneumococcal conjugate vaccine.