Study on the Safety and Efficacy of Meplazumab for Injection in Severe Patients With COVID-19

Inclusion Criteria: Age 18 to 80 (including 18 and 80 years old), male and female， By PCR detection method for nucleic acid amplification, laboratory confirmed SARS - CoV - 2 adults infected (within 72 hours before delivery) for the first time; Comply with national WeiJianWei "new coronavirus infection pneumonia diagnosis and treatment plan 9 (trial version)" clinical confirmed new coronavirus pneumonia patients (heavy); Agree to sign a consent form to test within 6 months after the effective non-pharmaceutical precautions; Participants must be able to understand and willing to participate in this research, this study and signed informed consent form (if incapacitated subjects, the researchers believe the subjects to the test in its own interests, should be signed by its legal guardian informed consent, or telephone inform consent (recording) and note it in the original medical records and other relevant documents). Exclusion Criteria: In the investigator's judgment, the subject has any physical examination results, laboratory abnormalities, and/or any history of disease that would endanger his safety by participating in the study; Comply with national WeiJianWei "new coronavirus infection pneumonia diagnosis and treatment plan 9 (trial version)" clinical diagnosis of type new coronavirus pneumonia in critically ill patients; Line 4 severe chronic kidney disease, or need dialysis (that is, the estimated glomerular filtration rate (eGFR) < 30 mL/min / 1.73 m2), or within 7 days of the serum creatinine increased 44.2 mu mol/L, or oliguria (< 400 mL / 24 hours) or no urine (< 100 mL / 24 hours); During pregnancy or lactation; Will be moved to within 72 hours is not the another hospital research center; Research on any drug allergies; Used as anticancer drugs, graft rejection drugs or immune regulating biological agents (group into the first 30 days or five half-life [will be subject to a long time]); Long-term use of corticosteroids and oral > 10 mg prednisone, a day for 3 months or more (allow oral every other day 10 mg prednisone); Randomization or research within 2 weeks before treatment and safety shall not be used during the follow-up period live vaccine (live attenuated); At the same time to participate in another clinical research subjects. A washout period of 5 half-lives (depending on the drug under study or 30 days from any previous study, whichever is longer) is required; Total bilirubin (TBL) > 2 x normal limit (ULN), and alanine aminotransferase (ALT) > 5 x ULN, or aspartate amino transferase (AST) > 5 x ULN, or alkaline phosphatase (> 5 x ULN; Platelet < 50 * 109 / L, or hemoglobin < 70 g/L; Researchers say other factors not appropriate in this test. Note: researchers should ensure that participants when screening meets all inclusion/exclusion standard. If a subject's status changes (including laboratory results) between screening and initial dosing and if the subject meets one of the exclusion criteria, the subject shall be excluded from the study.