The purpose of this study is to assess the immunogenicity and reactogenicity of GlaxoSmithKline (GSK) Biologicals' (formerly, SmithKline Beecham Biologicals) reduced-antigen-content acellular pertussis vaccine and reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine in comparison with Tedivax-Adult™/ Td-Rix™