The present clinical study will assess the immunogenicity and reactogenicity of the subsequent administration of Aventis Pasteur's DTacP-IPV//PRP~T combined vaccine (PENTAVAC™/PENTAXIM), as a three-dose primary vaccination in 6, 10 and 14 weeks of age schedule followed by a booster vaccination during the second year of life with the aim to cover the WHO EPI primary vaccination schedule at this age for diphtheria, tetanus, pertussis, poliomyelitis and Hib vaccines.