DAS181 for Severe COVID-19: Compassionate Use

Key Inclusion Criteria: 1. Positive for RNA of SARS-CoV-2 from respiratory specimens or blood specimens 2. Hypoxemic 3. Severe COVID-19 4. If female, subject must not be pregnant or nursing. 5. Non-vasectomized males are required to practice effective birth control methods 6. Capable of understanding and complying with procedures as outlined in the protocol as judged by the Investigator and able to sign informed consent form prior to the initiation of any screening or study-specific procedures. Exclusion Criteria: 1. ALT or AST\> 8 x ULN 2. (ALT or AST\> 3 x ULN) and (Total bilirubin\> 2.5 x ULN or INR\> 2.0 x ULN) 3. Female subjects who have a positive pregnancy test and are breastfeeding 4. Subjects using any other investigational antiviral drugs during the hospitalization before enrollment. 5. Subjects participating in other clinical trials 6. Subjects may be transferred to a non-participating hospital within 72 hours 7. People who cannot cooperate well due to mental illness, have no self-control, and cannot express clearly 8. Severe underlying diseases affecting survival 9. Critical COVID-19 requiring mechanical ventilator at the time enrolled