Patient Inclusion Criteria

1. Be ≥18 years of age 2. Provide adequate medical history to permit accurate stratification by health status 3. Prior to SARS CoV 2 infection, has no chronic or recurring requirement for supplemental oxygen 4. Have lower respiratory tract infection (LRTI) confirmed by imaging 5. Has laboratory-confirmation of the presence of SARS-CoV-2 in the respiratory tract 6. At the time of randomization, requires supplemental oxygen ≥2 LPM for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: 1. Respiratory rate ≥ 30 breaths/min 2. SpO2 ≤93% at rest 3. PaO2/FiO2≤300 mmHg 4. Showing the progression of lung lesions within 24 to 48h by >50% 7. If female, subject must meet one of the following conditions: 1. Not be of childbearing potential or 2. Be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception 8. Non-vasectomized males are required to practice effective birth control methods 9. Capable of understanding and complying with procedures as outlined in the protocol 10. Provides signed informed consent prior to the initiation of any screening or study-specific procedures

Patient Exclusion Criteria

1. At the time of randomization, classified as critical (life-threatening) disease 2. Subjects currently receiving any other investigational drug, as part of a clinical trial or under emergency approval for SARS-CoV-2 3. Subjects who are known asthmatic patients or HIV-positive 4. Subjects who are currently receiving inhaled biologics or anti-viral agents 5. Subjects with severe sepsis due to either their SARS-CoV-2 infection or a concurrent viral, bacterial, or fungal infection with vital organ failure or required vasopressors to maintain blood pressure 6. Subjects with Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), or Alkaline Phosphatase (ALP) ≥3x ULN and Total Bilirubin (TBILI) ≥2xULN 7. Female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug. 8. Psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance. 9. Subjects with known hypersensitivity to DAS181 and/or any of its components.