To evaluate the safety and efficacy of humanized Meplazumab for Injection in patients infected by 2019-nCoA.

According to the results of nonclinical study of humanized Meplazumab for Injection, a single dose will be used for the treatment. The treatment plan is first dose on the first day (0d) and second dose on the second day (1D) of the treatment period by intravenous(IV) infusion, each dose 10mg; The third dose will be given within 3-5 days after the second dose according to the patient's 2019-nCoV nucleic acid load, clinical manifestations and the overall evaluation of doctors, dose is 10mg. 30 mg of methylprednisolone will be given intravenously 30 minutes before each administration. Each subject will be evaluated the therapeutic effect within 28 days after the first administration, and to determine the preliminary therapeutic effect, safety and tolerability of humanized Meplazumab for Injection.

Inclusion Criteria:

• Men and women aged 18 to 75 years (inclusive)
• In line with the new coronavirus infection pneumonia diagnosis and treatment plan (trial version 4) issued by the Health Commission, patients with new coronavirus (2019 ncov) pneumonia were clinically diagnosed;
• The subjects must be able to understand the study and willing to participate in the study, and sign the informed consent (if the subjects with no behavioral ability think it is in their own interests to participate in the test, they should sign the informed consent by their legal guardian, or notify the consent by phone (recording) and explain it in the original medical record and other relevant documents).

Exclusion Criteria:

• Known or expected to have allergic reactions or a history of allergy to any of the ingredients treated in this trial;
• In the judgment of the investigator, there are other reasons that the patient is not suitable to participate in this study.