Study to Assess the Safety & Reactogenicity of GSK Biologicals' dTpa Vaccine (Boostrix) When Given at 6-8 Years of Age.

Inclusion Criteria: * A male or female between, and including, 6-8 years of age at the time of vaccination, * Written informed consent obtained from the parent or guardian of the subject, * Subjects who have received a total of 4 doses of DTP vaccine in the first 2 years of life, Exclusion Criteria: * subjects who have received previous DTP booster vaccination since administration of the fourth dose of vaccine in second year of life can not participate * Subjects with history of diphtheria, pertussis or tetanus diseases can not participate