The purpose of this primary vaccination study is to evaluate the immunogenicity, safety and reactogenicity of three doses of GSK Biologicals' MenC-TT (Neisseria meningitidis group C polysaccharide-tetanus toxoid) vaccine (2 different formulations) and of three doses of GSK Biologicals' Hib-MenC-TT (Haemophilus influenzae type b-MenC-TT) vaccine (2 different formulations) when given to infants in their 3rd, 4th, and 5th months of life. Concomitant vaccines were given to all children to complete the vaccination agenda.