Immunogenicity and Safety of GlaxoSmithKline Biologicals' MMRV Vaccine vs. ProQuad® in Children 12-14 Months of Age

Inclusion Criteria:

- Subjects for whom the investigator believes their parents/guardians can and will
comply with the requirements of the protocol.

- Male or female between 12 and 14 months of age at the time of first vaccination.

- Written informed consent obtained from the parent/guardian of the subject.

- Healthy subjects as established by medical history and clinical examination before
entering into the study.

- Have previously received 3 doses of 7-valent pneumococcal conjugate vaccine within the
first year of life.

Exclusion Criteria:

- Use of any investigational or non-registered product other than the study vaccine(s)
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.

- Chronic administration of immunosuppressants or other immune-modifying drugs within
six months prior to the first vaccine dose.

- Planned administration/ administration of a vaccine not foreseen by the study protocol
from 30 days prior to vaccination until 42 days after vaccination, except for
influenza vaccine.

- Previous vaccination against measles, mumps, rubella and/or varicella.

- Previous vaccination against hepatitis A or receipt of a fourth dose of pneumococcal
conjugate vaccine.

- History of measles, mumps, rubella and/or varicella/zoster diseases.

- Known exposure to measles, mumps, rubella and/or varicella/zoster within 30 days prior
to the start of the study.

- Any confirmed or suspected immunosuppressive or immunodeficient condition, based on
medical history and physical examination, including human immunodeficiency virus
infection.

- A family history of congenital or hereditary immunodeficiency.

- History of allergic disease or reactions likely to be exacerbated by any component of
the vaccines.

- Major congenital defects or serious chronic illness.

- History of any neurologic disorders or seizures. Uncomplicated febrile convulsions are
not an exclusion criterion.

- Residence in the same household as the following persons:

- New-born infants (0-4 weeks of age).

- Pregnant mother/women with a negative history of chickenpox disease and without
recorded vaccination against chickenpox.

- Pregnant women at or beyond 28 weeks gestation regardless of varicella
vaccination status or varicella disease history.

- Persons with known immunodeficiency.

- Acute disease at the time of enrolment. All vaccines can be administered to persons
with a minor illness.

- Administration of polyclonal immunoglobulins and/or any blood products during the six
months before entering the study or planned administration during the study period.

- Contra-indications to commercially available vaccines used in this study (Havrix®,
Prevnar®, ProQuad®).