A Phase I/II Clinical Trial in Healthy People Aged 18 Years and Above

Study Overview
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Brief Summary
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This clinical trial is a phase I/II clinical trial to evaluate the safety, immunogenicity and immune persistence of COVID-19 mRNA vaccine in healthy people aged 18 years and above.

Detailed Description
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This is the clinical trial including an open-label, single-arm Phase I study and a subsequent randomized, blind, placebo-parallel controlled Phase II study to evaluate the safety, immunogenicity and immune persistence of COVID-19 mRNA vaccine in healthy people aged 18-60 years and ≥18 years respectively, whose locations or circumstances put them at appreciable risk of acquiring COVID-19 and/or SARS-CoV-2 infection.

Official Title
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A Phase I/II Clinical Trial to Evaluate the Safety, Immunogenicity and Immune Persistence of COVID-19 mRNA Vaccine in Healthy People Aged 18 Years and Above.

Conditions
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COVID-19 Pandemic

Intervention / Treatment
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* Biological: COVID-19 mRNA vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: People aged 18-60 years (both inclusive) for phase 1 and aged ≥18 years for phase 2； Medical history and physical examination indicating as a healthy person; The female participant or the spouse (or partner) of the male participant in child-birthing age agrees to use effective contraceptive measure throughout the whole course of this clinical trial. Those who are participating in this clinical trial voluntarily, have signed the informed consent form, and been able to understand and comply with the requirements of the clinical trial protocol. Exclusion Criteria: Confirmed cases or history of SARS-CoV-2 infection; Has a history of SARS and MERS virus infection; Has fever (axillary temperature ≥37.3℃), dry cough, fatigue, nasal congestion, runny nose, sore throat, myalgia, diarrhea, shortness of breath, and dyspnea within 14 days before vaccination; Positive urine pregnancy test； Axillary temperature ≥37.3℃ at the day vaccinated; History of severe allergic reactions to vaccination (such as acute allergic reactions, urticaria, dyspnea, angioneurosis, edema, etc.) or allergies to known components of COVID-19 mRNA vaccine; History or family history of convulsions, epilepsy, encephalopathy, or mental illness; Suffering from congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; Known suffering from diseases including: acute respiratory disease (such as flu-like illness, acute cough, sore throat), severe cardiovascular disease, kidney disease, uncontrolled hypertension (systolic blood pressure >150 mmHg, diastolic blood pressure >90 mmHg), diabetes complications, malignant tumor, all sorts of acute illness or chronic diseases acute phase; Diagnosis with congenital or acquired immunodeficiency, HIV infection, lymphoma, leukemia, or other autoimmune disease; Abnormal coagulation function (such as lack of coagulation factor, coagulation disorders); Receiving anti-tuberculosis treatment; Long-term receipt (continuous≥7 days) of glucocorticoid (reverence value for dose: amount to≥20 mg/d prednisone equivalent), except inhaled, topical, nasal, aural and ophthalmic corticosteroids, within 6 months before screening; Receipt of immunotherapy or immunosuppressant within 3 months (continuous oral or infusion for more than 14 days); Receipt of live attenuated vaccine within 28 days prior to vaccination and other vaccines within 14 days prior to vaccination; Receipt of blood products within 3 months prior to vaccination Receipt of other study drugs within 6 months prior to vaccination; Receipt of any SARS-COV-2 vaccine; Other situations judged by the investigators that are not suitable for participating in this clinical trial.

Ages Eligible for Study
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Minimum Age: 18 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: Sequential Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low dose group with mRNA vaccine<br>25μg with COVID-19 mRNA vaccine | Biological: COVID-19 mRNA vaccine<br>* Intramuscular injection, COVID-19 mRNA vaccine/placebo, 21 days interval<br>|
| Placebo Comparator: Low dose group with placebo<br>Low dose group with placebo | Biological: COVID-19 mRNA vaccine<br>* Intramuscular injection, COVID-19 mRNA vaccine/placebo, 21 days interval<br>|
| Experimental: High dose group with mRNA vaccine<br>45μg with COVID-19 mRNA vaccine | Biological: COVID-19 mRNA vaccine<br>* Intramuscular injection, COVID-19 mRNA vaccine/placebo, 21 days interval<br>|
| Placebo Comparator: High dose group with placebo<br>High dose group with placebo | Biological: COVID-19 mRNA vaccine<br>* Intramuscular injection, COVID-19 mRNA vaccine/placebo, 21 days interval<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| local/systemic solicited adverse reaction/events | The incidence of local/systemic solicited adverse reaction/events | up to 6 days after each dose | 
| unsolicited adverse events | The incidence of unsolicited adverse events | up to 21 days and up to 28 days after the first and second dose of immunization, respectively | 
| The incidence of SAE | The incidence of SAE from the first dose of vaccination to 28 days after the full course of immunization | up to 28 days after the full course of immunization | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The seroconversion rate, 2-fold or 4-fold rise and GMT/GMI of the SARS-COV-2 S-protein specific antibody (specific total antibody/IgG antibody) and neutralizing antibody | The seroconversion rate, 2-fold or 4-fold rise and GMT/GMI of the SARS-COV-2 S-protein specific antibody (specific total antibody/IgG antibody) and neutralizing antibody 14 days after the full immunization in the subjects who take two doses as protocol specified | 14 days after the full immunization | 
| The incidence of SAE | The incidence of SAE within the 29th  365th day after the full course of immunization | the 29th  365th day after the full course of immunization | 
| Changes in laboratory abnormal parameters | Changes in laboratory abnormal parameters in the participants who take at least of one dose | after at least of one dose |