A phase III randomized multi-center study to assess the immunogenicity of three doses of Pediarix®, Prevnar® and ActHIB® given to healthy infants at 2, 4 and 6 months of age when administered with GlaxoSmithKline (GSK) Biologicals' two-dose oral live attenuated human rotavirus (HRV) vaccine given during the same vaccination visit (at 2 and 4 months of age) or given separately (at 3 and 5 months of age).