Immunogenicity and Safety of S.Flexneriza-S.Sonnei Bivalent Conjugate Vaccine in Volunteers Aged From 3 Months to 5 Years Old

Inclusion Criteria: * Health infants and children aged from 3 months to 5 years old. * Subject or legal representative who consent and has signed written informed consent. * Subject and parent/guardian who is able to comply with all study procedures. * Subject who did't receive blood products within 30 days ,immune with any live vaccine within 14 days and inactivated vaccine within 7 days before vaccination. * Subject who haven't immuned with diarrhea vaccination,3-11 months health infants who haven't immuned with Haemophilus b Conjugate vaccination,or had a history of Hib vaccination before the age of 1 but no history of vaccination after 1 year of age,and the interval between the day of the enrollment and the previous dose is more than one month. * Axillary temperature ≤37.0 ℃. Exclusion Criteria: * Febrile illness (temperature ≥ 38°C) in the 3 days or in the acute phase of the disease / active period. * Subject who have symptoms such as diarrhea, abdominal pain, and pus and bloody stools in the past 3 days. * Subject who are allergic to tetanus toxoid. * Allergic history after vaccination. * Immunodeficiency diseases patients (such as perianal abscess suggests that there may be immunodeficiency in infants and young children) who administered with immunosuppressive agents (≥14 days). * Subject who are suffering from serious chronic diseases, cardiovascular disease,liver or kidney disease. * Subject with congenital malformations, drug allergies, convulsions, epilepsy, history of craniocerebral trauma, encephalopathy and psychosis, or family history. * Subject who diagnosis of thrombocytopenia or other history of coagulopathy may cause intramuscular contraindication. * Children with abnormal labor（pregnancy week\<37w,\>42w）,birth weight (\<2500g,\>4000g), asphyxia rescue history(Only applicable to 3-5 months old group). * Subject who plan to participate in or is in any other drug clinical trial. * Any condition that, in the judgment of investigator, may affect trial assessment.