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.

Inclusion Criteria:

• Healthy permanent residence 2 months to 5 years old.
• Subjects who the investigator believes will comply with the requirements of the protocol should be enrolled in the study.
• Subjects and parent/guardian able to attend all scheduled visits and comply with all study procedures.
• Axillary temperature ≤37.0 ℃.

Exclusion Criteria:

• History of Haemophilus influenzae type b infection or vaccination of Haemophilus influenzae type b conjugate vaccine.
• Allergic history or any SAE after vaccination, such as allergy, urticaria, dyspnea, angioedema, celialgia.
• Receipt of blood or blood-derived products in the 3 months preceding vaccination
• Participation in another clinical study investigating a vaccine, drug in the 30 days preceding vaccination.
• Receipt of any live virus vaccine in the 15 days preceding vaccination.
• Receipt of any subunit vaccine and inactivated vaccine in the 7 days before vaccination.
• Febrile illness (temperature ≥ 38°C) in the 3 days or any acute illness/infection in the 7 days preceding vaccination.
• Thrombocytopenia.
• History of treatment for thyroid gland disease.
• Functional or anatomic asplenia.
• History of eclampsia, epilepsy, encephalopathy and mental disease or family disease.
• Any condition that, in the judgment of investigator, may affect trial assessment.