This study will assess the immunogenicity and reactogenicity of the candidate GSK Biologicals' reduced antigen diphtheria and tetanus toxoids and acellular pertussis- inactivated poliovirus vaccine when administered to healthy subjects aged ≥ 15 years in Germany and ≥ 18 years in France compared to Boostrix™ and inactivated poliovirus vaccine administered separately, and with Revaxis®