Efficacy, Immunogenicity and Safety of S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine in Volunteers Aged From 6 Months to 5 Years

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the efficacy, immunogenicity and safety of S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine in infants and children aged from 6 months to 5 years.

Official Title
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A Multicenter, Randomized, Double-blind, Placebo-Controlled Phase III Clinical Trial to Evaluate the Efficacy, Immunogenicity and Safety of S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine in Volunteers Aged From 6 Months to 5 Years

Conditions
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Dysentery, Shigellosis

Intervention / Treatment
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* Biological: S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine
* Biological: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Infants and children aged from 3 months to 5 years old; The legal representative voluntarily agrees to participate in the study and signed the informed consent form; The legal representative voluntarily agrees to comply with the requirements of the clinical study protocol, and they can participate in all planned follow-up; Subjects who didn't immuned with attenuated live vaccine within 14 days and inactivated vaccine within 7 days before vaccination; Axillary temperature ≤37.0℃; According to the medical history, physical examination and the judgment of the researcher, it is determined that the subject is in good physical condition. Exclusion Criteria: Previous proven history of bacillary dysentery; Subjects who are allergic to tetanus toxoid, and have any history of other vaccination or drug allergy, or a fever above 39.5 ℃ after previous vaccination; Within 3 days before vaccination, suffering from acute diseases or in the acute episode of chronic disease or using antipyretic, analgesic and antiallergic drugs (such as acetaminophen, ibuprofen, etc.); Had severe bowel disease, and had symptoms such as diarrhea, abdominal pain, pus and blood stool and other symptoms in the past 3 days; With pathological jaundice confirmed by existing diagnosis; History of thrombocytopenia or other coagulation disorders with definite diagnosis; Known or suspected immunological deficiency (such as perianal abscess, which indicates that infants may have immune deficiency), and received long-term (≥14 days) immunosuppressive therapy (radiotherapy, chemotherapy, systemic glucocorticosteroids≥2 mg/kg/day, antimetabolic drugs and cytotoxic drugs) within half a year before vaccination, or confirmed that the parents were HIV infected; Received immunoglobulin / blood products treatment within 3 months before vaccination; Severe congenital malformations (functional impairment of important organs), severe malnutrition, developmental disorders and serious genetic diseases (such as severe thalassemia); Subjects with the following diseases: Serious liver and kidney diseases, cardiovascular diseases, malignant tumors and other chronic diseases; Diagnosis with infectious diseases such as tuberculosis, viral hepatitis and so on; Severe asthma; Systemic rash, dermatophyte, skin suppuration or blister; History or family history of convulsion, epilepsy, encephalopathy, mental illness; Planning to participate or currently participating in clinical trials of other vaccines or drugs; Any situation that the investigator believed may affect the study evaluation.

Ages Eligible for Study
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Minimum Age: 6 Months
Maximum Age: 5 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental group<br>S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine, 0.5ml/dose, 2 doses with an interval of 30 days. | Biological: S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine<br>* Single intramuscular dose contains 10 µg of S. flexneri 2a polysaccharide and S. sonnei polysaccharide respectively.<br>|
| Placebo Comparator: Placebo group<br>Aluminium phosphate adjuvant, 0.5ml/dose, 2 doses with an interval of 30 days. | Biological: Placebo<br>* Single intramuscular dose contains 0.15 0.25 mg of aluminum ion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Efficacy study of S. Flexneriza-S. Sonnei Bivalent Conjugate Vaccine as assessed by protective rate | Evaluate the protective rate for bacillary dysentery | 30 day after each vaccination |