Immunogenicity and Safety of A Group A, C Polysaccharide Meningococcal and Type b Haemophilus Influenzal Conjugate Vaccine in Infants and Children

For the children (aged from 2 to 5 years old) Inclusion Criteria: * Healthy subjects aged from 2 to 5 years old of normal intelligence. * The subjects' guardians are able to understand and sign the informed consent. * Subjects established as healthy after medical history questioning, physical examination and clinical decision and in accordance with vaccination requirements of the investigational vaccine. * Subjects who can comply with the requirements of the clinical trial program according to the researcher's views. * Subjects who have never received group A, C polysaccharide meningococcal vaccine and type b haemophilus Influenzal vaccine. * Subjects with temperature \<37°C on axillary setting. Exclusion Criteria: * Subject who has a medical history of Meningitis; * Subject that has a medical history of any of the following: allergies, seizures, epilepsy, encephalopathy history and so on; * Subject who is allergic with tetanus toxoid components; * Subject suffering from thrombocytopenia or other coagulation disorder may lead to contraindication to intramuscular injection; * Subject who has a history of allergic reactions; * Any known immunological dysfunction; * Had received gamma globulin or immune globulin, in the past two weeks * Subject suffering from congenital malformations, dysgenopathy or serious chronic disease; * Any acute infections * Any condition that in the opinion of the investigator, may interfere with the evaluation of study objectives For the infants (aged from 6 to 23 months old) Inclusion Criteria: * Healthy subjects aged from 6 months to 23 months old of normal intelligence. * The subjects' guardians are able to understand and sign the informed consent. * Subjects established as healthy after medical history questioning, physical examination and clinical decision and in accordance with vaccination requirements of the investigational vaccine. * Subjects who can comply with the requirements of the clinical trial program according to the researcher's views. * Subjects who have never received group A, C polysaccharide meningococcal vaccine and type b haemophilus Influenzal vaccine. * Subjects with temperature\<37°C on axillary setting. Exclusion Criteria for the first vaccination: * Subject who has a medical history of Meningitis; * Subject that has a medical history of any of the following: allergies, seizures, epilepsy, encephalopathy history and so on; * Subject who is allergic with tetanus toxoid components; * Subject suffering from thrombocytopenia or other coagulation disorder may lead to contraindication to intramuscular injection; * Subject who has a history of allergic reactions; * Any known immunological dysfunction; * Had received gamma globulin or immune globulin, in the past two weeks * Subject suffering from congenital malformations, dysgenopathy or serious chronic disease; * Any acute infections * Any condition that in the opinion of the investigator, may interfere with the evaluation of study objectives Exclusion Criteria for the second vaccination: * Had any Grade 3 or Grade 4 adverse reactions or events occurred since the first vaccination * Any situation meets the exclusion criteria stated in the exclusion criteria for first dose; * Any condition the investigator believed may affect the evaluation of the vaccine.