This study is evaluating the safety and immunogenicity of GSK Biologicals' Hib-MenCY-TT vaccine compared to a control group receiving licensed Hib conjugate vaccine, each administered at 2, 4, and 6 months of age, and compared to licensed meningococcal serogroups A, C, Y, and W-135 polysaccharide vaccine administered at 3 to 5 years of age.