This open, randomised controlled trial studied the immunogenicity and reactogenicity of two combined low-dose diphtheria, tetanus and acellular pertussis vaccines (Td5aP-IPV, REPEVAX, Aventis Pasteur MSD; and Td5aP, COVAXIS, Aventis Pasteur MSD + OPV, GlaxoSmithKline) in comparison with a standard dose diphtheria pre-school booster vaccine (DT2aP-IPV, TETRAVAC, Aventis Pasteur MSD) in a populat...