Immunogenicity and Safety of Meningococcal Groups A and C and Haemophilus b Conjugate Vaccine in Infants 2 to 5 Months of Age

Inclusion Criteria: * Health infants aged 2 to 5 months. * Legal guardian has signed written informed consent. * Guardian may finish the whole visit in the judgment of investigator. * 2-5 months health infants who haven't immuned with any Meningococcal A and C Conjugate Vaccine or Haemophilus b Conjugate Vaccine. * Subject who did't vaccinated with any live vaccine within 14 days or inactivated vaccine within 10 days before vaccination. Exclusion Criteria: * Fever, body temperature ≥37.1℃. * History of severe allergic reaction that needs medical intervention including throat swelling, dyspnea, hypotension or shock; History of allergic reaction to vaccine or to any of the vaccine components especially to tetanus toxoid or history of other severe adverse reaction to vaccine. * Clear diagnosis of thrombocytopenia or history of other coagulation disorders that may cause contraindications of intramuscular injection. * Subject with history of abnormal labor, asphyxia rescue history,congenital malformations,eccyliosis or severe chronic disease. * Severe cardiovascular or liver and kidney disease, active tuberculosis and HIV infection. * Subject with encephalopathy, uncontrolled epilepsy and other progressive nervous system disease. * Subject suffer from acute disease, severe chronic disease, acute episode of chronic disease and febrile illness (temperature ≥ 38°C) within 3 days. * Any condition that, in the judgment of investigator, subject is not suitable for participation in this clinical trial.