Evaluation of the Safety and Immunogenicity of Hepatitis A Vaccine

To evaluate the safety and immunogenicity of Hepatitis A (Live) Vaccine, Freeze-dried produced by Changchhun Institute of Biological Products Co., Ltd, we design this randomized, parallel controlled study. 450 subjects are divided into 3 groups, including 1 experimental group and 2 control groups (Research Group 1, 2, and 3), each group assigned 150 subjects respectively.

All subjects are aged 18-24 months old.

150 subjects from Research Group 1 will be administrated with one dose of Hepatitis A (Live) Vaccine, Freeze-dried produced by Changchhun Institute of Biological Products Co., Ltd. Blood samples are collected before vaccination and one month (30 days) later.

150 subjects from Research Group 2 will be administrated with one dose of Hepatitis A（Live）Vaccine，Freeze-dried produced by Zhejiang Pukang Biotechnology Co., Ltd. Blood samples are collected before vaccination and one month (30 days) later.

150 subjects from Research Group 3 will be administrated with one dose of Hepatitis A (Live) Vaccine, Freeze-dried produced by Institute of Medical Biology, Chinese Academy of Medical Sciences. Blood samples are collected before vaccination and one month (30 days) later.

To evaluate the immunogenicity, we will detect and compare the seroconversion rates, and antibody geometric mean concentrations. The safety of all groups will be monitored as well.

• Hepatitis A (Live) Vaccine, Freeze-dried produced by Changchun (Biological): Administration of one dose of Hepatitis A (Live) Vaccine, Freeze-dried produced by Changchun. 0.5ml per dose
• Hepatitis A (Live) Vaccine, Freeze-dried produced by Zhejiang (Biological): Administration of one dose of Hepatitis A (Live) Vaccine, Freeze-dried produced by Zhejiang. 0.5ml per dose.
• Hepatitis A (Live) Vaccine, Freeze-dried produced by the Institute of Medical Biology, CAMS (Biological): Administration of one dose of Hepatitis A (Live) Vaccine, Freeze-dried produced by the Institute of Medical Biology, Chinese Academy of Medical Sciences. 1.0ml per dose.

Primary outcomes

• Antibody Seroconversion rate [4 months]: Blood samples were collected before and 30 (+ 10) days after immunization. Antibody level and antibody seroconversion rate of HAV-IgG will detect in laboratory. The antibody seroconversion rate of HAV-IgG must maintain the baseline as the other two comparators' products.

Secondary outcomes

• Antibody Geometric Mean Titer (GMT) [4 months]: Antibody GMT will detect in laboratory. The antibody GMT must maintain the baseline as the other two comparators' products.
• Adverse Events Incidence rate [6 months]: Analyse the numbers and rates of participants who suffered from adverse events following immunization.

Sex: All, ages: 18 Months to 24 Months, accepts healthy volunteers

Inclusion Criteria:

1. subjects aged from 18 to 24 months old at the date of recruitment;
2. with informed consent signed by parent(s) or guardians;
3. parent(s) or guardians are able to attend all planned clinical appointments and obey and follow all study instructions;
4. subjects have not been vaccinated with any type of Hepatitis A vaccines;
5. subjects have no Hepatitis A disease and contraindication of vaccination;
6. subjects did not receive any vaccines within 14 days;
7. before joining this trial, subjects must be qualified and passed their medical history and clinical examinations, and axillary's temperature must be ≤37℃.

Exclusion Criteria:

1. Subjects with history of allergy, convulsion, epilepsy, encephalopathy and psychosis or family history;
2. Allergic to any ingredient of vaccine or with allergy history to any vaccine;
3. Patients with immunodeficiency, in process of cancer treatment, immunosuppressive therapy (oral steroids) or HIV induced hypoimmunity, or in close contact with any family members who has congenital immune diseases;
4. Receive non-specific immunoglobulin within 1 month before recruitment;
5. Subjects with acute febrile diseases with body temperature > 37.0 ℃ or infectious diseases;
6. Subjects with a history of thrombocytopenia or other coagulation disorders that may be contraindicated for hypodermic injection;
7. With known or suspected concurrent diseases include respiratory disease, acute infection or active chronic disease;
8. With severe cardiovascular diseases (Pulmonary heart disease, Pulmonary edema, hypertension cannot be controlled to normal range by drugs), liver and kidney diseases and diabetic complications;
9. Various infectious, suppurative or allergic dermatitis;
10. Other circumstances judged by investigators that are not suitable for this clinical trial.

• Shaobai Zhang, Principal investigator, Shaanxi Provincial Center for Disease Control and Prevention