JS016-002-Ib/II is a randomized, double-blinded, placebo-controlled study, to investigate the safety, PK profiles, preliminary efficacy and immunogenicity of intravenous Recombinant Human Anti-SARS-CoV-2 Monoclonal Antibody (JS016) in participants with mild and moderate COVID-19 or of SARS-CoV-2 Asymptomatic Infection.

Three doses of JS016 are to be investigated, including 25mg/kg, 50mg/kg and 100mg/kg, given as single dose of intravenous infusion. In total, 90 participants will be enrolled with 30 participants each for 25, 50 and 100mg/kg dose cohort at a ratio of 2:1 to receive investigational product or placebo treatment, respectively.

"Each participant will receive JS016 or matched placebo intravenous infusion on D1 (randomizing day). Non-pharmaceutical supportive background therapy (e.g. oxygen inhalation) for COVID-19 is allowed per clinical needs.

Investigators will be kept blinded to review the preliminary efficacy and safety data on a regular basis. Meanwhile, a study evaluation team (SET) composed of medical monitors, safety assessors and statisticians will be set up to review the study status, safety and preliminary efficacy of the participants at the pre-specified time points or as necessary.

Inclusion Criteria:

1. Age of 18-65 years (inclusive) ,women or man
2. SARS-CoV-2 detected in the diagnostic specimen (nasopharyngeal swab)
3. High homology of viral gene sequencing with the known SARS-CoV-2."
4. Mild/moderateillness COVID-19 or SARS-CoV-2 asymptomatic infection
5. Within 7 days from the onset time of symptoms to randomization or within 5 days from the first time of SARS-CoV-2 positive test to randomization with required viral load
6. No plan of pregnancy and being willing to use effective contraceptive measures
7. Signed the informed consent form, sufficiently understanding of the content

Exclusion Criteria:

1. positive IgM/IgG against SARS-CoV-2 prior to randomization.
2. Severeor critical illness
3. Uncontrolled hypertension, cardiovascular/cerebrovascular diseases,lung diseases
4. Type 1 diabetes, or newly diagnosed or poorly controlled type 2 diabetes
5. Liver and kidney dysfunction, immune or inflammatory diseases, infections, surgery, tumors, and other major diseases
6. History of SARS-CoV-2 vaccination or participation in clinical trial with neutralizing antibody against SARS-CoV-2.
7. Use of therapeutic biologics within 3 months prior to screening, or within the elimination period (5 half-lives) of such drugs as the day of dosing
8. Has participated in any other interventional clinical study involving anstudy drug within 3 months prior to screening, or within the elimination period (5 half-lives) of the study drug as the day of dosing
9. Platelets and hemoglobin test results during screening period are abnormal and have clinical significanc.
10. Anaphylaxis, urine drug screening, alcohol dependence, lactation during pregnancy, blood loss, and others