Haemophilus influenza type b (Hib) remains a serious global health threat associated with high mortality and morbidity in young children. In China, The overall impact of Hib-related infections and the extent of coverage of Hib conjugate vaccines are unclear.Generally, vaccination has been considered the most effective way to prevent infection against Hib.In order to evaluate safety and immunogenicity of a haemophilus influenzae type b (Hib) conjugate vaccine developped by Chengdu Olymvax Biopharmaceuticals Inc. a phase III clinical trial is planned to conduct in healthy infants and children in China.

Haemophilus influenza type b (Hib) remains a serious global health threat associated with high mortality and morbidity in young children. In China, The overall impact of Hib-related infections and the extent of coverage of Hib conjugate vaccines are unclear.Generally, vaccination has been considered the most effective way to prevent infection against Hib.In order to evaluate safety and immunogenicity of a haemophilus influenzae type b (Hib) conjugate vaccine developped by Chengdu Olymvax Biopharmaceuticals Inc. a randomized, positive-controlled, non-inferiority phase III clinical trial is planned to conduct in healthy infants and children in China.

Inclusion Criteria:

• Healthy children aged 3-5 months/ 6-11 months/ 1-5 y for each age group
• Without vaccination history of Hib conjugate vaccine
• One of his/her guardians is able to understand and sign the informed consent
• Subjects' guardian can and will comply with the requirements of the protocol
• Subjects with temperature <=37.0°C on axillary setting

Exclusion Criteria:

• Subject who has a medical or family history of any of the following: allergic history, seizure, epilepsy, brain or mental disease
• Subject who is allergic to any ingredient of the vaccines
• Subject with damaged or low immune function which has already been known
• Subject who had a Hib disease medical history
• Subject with acute febrile illness or infectious disease
• Major congenital defects, developmental disorders or serious chronic illness
• Thrombocytopenia, blood coagulation disorder or bleeding difficulties with intramuscular injection
• Subject who has serious allergic history
• Subject with other medical history not suitable for vaccination such as difficulty for blood collection
• Any prior administration of immunodepressant or corticosteroids in last 6 months
• Any prior administration of blood products in last 3 months
• Any prior administration of other research medicine/vaccine in last 30 days
• Any prior administration of any attenuated live vaccine in last 14 days
• Any prior administration of subunit or inactivated vaccines in last 7 days, such as pneumococcal vaccine
• Any medical, psychological, social or other condition judged by investigator, that may interfere subject's compliance with the protocol or his/her guardian's signature on informed consent