 The study will evaluate the safety and immunogenicity of a haemophilus influenzae type b conjugate vaccine Hib in Healthy Children 2 Months to 5 Years of Age who have not been previously immunized with a Hib vaccine. Children 2 to 5 months of age will receive 3 doses of Hib vaccine, Children 6 to 11 months of age will receive 2 doses of Hib vaccine, Children 1 to 5 years of age will receive 1 dose of Hib vaccine, with each dose given approximately 1 month apart. 