Immunogenicity and Safety Study of GlaxoSmithKline (GSK) Biologicals' Combined Measles-mumps-rubella (MMR) Vaccine in Subjects Four to Six Years of Age

Immunogenicity and Safety Study of GlaxoSmithKline (GSK) Biologicals' Combined Measles-mumps-rubella (MMR) Vaccine in Subjects Four to Six Years of Age