1. subjects may not be on hospice care or, in the opinion of the investigator, have a low chance of survival during the first 10 days of treatment 2. subjects with alanine aminotransferase (alt), aspartate aminotransferase (ast), or alkaline phosphatase (alp) ≥3x uln and total bilirubin (tbili) ≥2x uln note: subjects with alt/ast/alp ≥ 3x uln and tb ≥2x uln that have been chronically stable (for \>1 year on more than one assessments) due to known liver pathology including malignancy (primary or metastasis), chronic medications, transplantation, or chronic infection will not be excluded 3. female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug 4. subjects taking any other investigational drug used to treat pulmonary infection. 5. psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance 6. subjects with known hypersensitivity to das181 and/or any of its components 7. subjects with severe sepsis due to either their baseline sad-rv infection or a concurrent viral, bacterial, or fungal infection and meet at least one of the following criteria: * has evidence of vital organ failure outside of the lung (e.g., liver, kidney) * requires vasopressors to maintain blood pressure for covid-19 sub study: 1. subjects requiring invasive mechanical, bi-pap or cpap ventilation at randomization. 2. subjects receiving any other investigational or empiric treatment for sars-2-cov (either as part of a clinical trial or under emergency approval (approved agents for the management of symptoms, e.g., fever, are permitted). 3. subjects who are known hiv-positive (and not undetectable at most recent hiv rna assessment) 4. subjects who are currently taking immunomodulating biologics (e.g, interferons, interleukin) 5. subjects with severe sepsis due to either their sars-cov-2 infection or a concurrent viral, bacterial, or fungal infection and meeting at least one of the following criteria: * have evidence of vital organ failure outside of the lung (e.g., liver, kidney) * require vasopressors to maintain blood pressure 6. subjects meeting exclusion criteria #2, 3, 5 and 6 of the main study

1. subjects may not be on hospice care or, in the opinion of the investigator, have a low chance of survival during the first 10 days of treatment 2. subjects with alanine aminotransferase (alt), aspartate aminotransferase (ast), or alkaline phosphatase (alp) ≥3x uln and total bilirubin (tbili) ≥2x uln note: subjects with alt/ast/alp ≥ 3x uln and tb ≥2x uln that have been chronically stable (for \>1 year on more than one assessments) due to known liver pathology including malignancy (primary or metastasis), chronic medications, transplantation, or chronic infection will not be excluded 3. female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug 4. subjects taking any other investigational drug used to treat pulmonary infection. 5. psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance 6. subjects with known hypersensitivity to das181 and/or any of its components 7. subjects with severe sepsis due to either their baseline sad-rv infection or a concurrent viral, bacterial, or fungal infection and meet at least one of the following criteria: * has evidence of vital organ failure outside of the lung (e.g., liver, kidney) * requires vasopressors to maintain blood pressure for covid-19 sub study: 1. subjects requiring invasive mechanical, bi-pap or cpap ventilation at randomization. 2. subjects receiving any other investigational or empiric treatment for sars-2-cov (either as part of a clinical trial or under emergency approval (approved agents for the management of symptoms, e.g., fever, are permitted). 3. subjects who are known hiv-positive (and not undetectable at most recent hiv rna assessment) 4. subjects who are currently taking immunomodulating biologics (e.g, interferons, interleukin) 5. subjects with severe sepsis due to either their sars-cov-2 infection or a concurrent viral, bacterial, or fungal infection and meeting at least one of the following criteria: * have evidence of vital organ failure outside of the lung (e.g., liver, kidney) * require vasopressors to maintain blood pressure 6. subjects meeting exclusion criteria #2, 3, 5 and 6 of the main study

subjects may not be on hospice care or, in the opinion of the investigator, have a low chance of survival during the first 10 days of treatment subjects with alanine aminotransferase (alt), aspartate aminotransferase (ast), or alkaline phosphatase (alp) ≥3x uln and total bilirubin (tbili) ≥2x uln note: subjects with alt/ast/alp ≥ 3x uln and tb ≥2x uln that have been chronically stable (for >1 year on more than one assessments) due to known liver pathology including malignancy (primary or metastasis), chronic medications, transplantation, or chronic infection will not be excluded female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug subjects taking any other investigational drug used to treat pulmonary infection. psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance subjects with known hypersensitivity to das181 and/or any of its components subjects with severe sepsis due to either their baseline sad-rv infection or a concurrent viral, bacterial, or fungal infection and meet at least one of the following criteria: has evidence of vital organ failure outside of the lung (e.g., liver, kidney) requires vasopressors to maintain blood pressure for covid-19 sub study: subjects requiring invasive mechanical, bi-pap or cpap ventilation at randomization. subjects receiving any other investigational or empiric treatment for sars-2-cov (either as part of a clinical trial or under emergency approval (approved agents for the management of symptoms, e.g., fever, are permitted). subjects who are known hiv-positive (and not undetectable at most recent hiv rna assessment) subjects who are currently taking immunomodulating biologics (e.g, interferons, interleukin) subjects with severe sepsis due to either their sars-cov-2 infection or a concurrent viral, bacterial, or fungal infection and meeting at least one of the following criteria: have evidence of vital organ failure outside of the lung (e.g., liver, kidney) require vasopressors to maintain blood pressure subjects meeting exclusion criteria #2, 3, 5 and 6 of the main study

subjects may not be on hospice care or, in the opinion of the investigator, have a low chance of survival during the first 10 days of treatment subjects with alanine aminotransferase (alt), aspartate aminotransferase (ast), or alkaline phosphatase (alp) ≥3x uln and total bilirubin (tbili) ≥2x uln note: subjects with alt/ast/alp ≥ 3x uln and tb ≥2x uln that have been chronically stable (for >1 year on more than one assessments) due to known liver pathology including malignancy (primary or metastasis), chronic medications, transplantation, or chronic infection will not be excluded female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug subjects taking any other investigational drug used to treat pulmonary infection. psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance subjects with known hypersensitivity to das181 and/or any of its components subjects with severe sepsis due to either their baseline sad-rv infection or a concurrent viral, bacterial, or fungal infection and meet at least one of the following criteria: has evidence of vital organ failure outside of the lung (e.g., liver, kidney) requires vasopressors to maintain blood pressure for covid-19 sub study: subjects requiring invasive mechanical, bi-pap or cpap ventilation at randomization. subjects receiving any other investigational or empiric treatment for sars-2-cov (either as part of a clinical trial or under emergency approval (approved agents for the management of symptoms, e.g., fever, are permitted). subjects who are known hiv-positive (and not undetectable at most recent hiv rna assessment) subjects who are currently taking immunomodulating biologics (e.g, interferons, interleukin) subjects with severe sepsis due to either their sars-cov-2 infection or a concurrent viral, bacterial, or fungal infection and meeting at least one of the following criteria: have evidence of vital organ failure outside of the lung (e.g., liver, kidney) require vasopressors to maintain blood pressure subjects meeting exclusion criteria #2, 3, 5 and 6 of the main study

1. subjects may not be on hospice care or, in the opinion of the investigator, have a low chance of survival during the first 10 days of treatment 2. subjects with alanine aminotransferase (alt), aspartate aminotransferase (ast), or alkaline phosphatase (alp) ≥3x uln and total bilirubin (tbili) ≥2x uln note: subjects with alt/ast/alp ≥ 3x uln and tb ≥2x uln that have been chronically stable (for >1 year on more than one assessments) due to known liver pathology including malignancy (primary or metastasis), chronic medications, transplantation, or chronic infection will not be excluded 3. female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug 4. subjects taking any other investigational drug used to treat pulmonary infection. 5. psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance 6. subjects with known hypersensitivity to das181 and/or any of its components 7. subjects with severe sepsis due to either their baseline sad-rv infection or a concurrent viral, bacterial, or fungal infection and meet at least one of the following criteria: - has evidence of vital organ failure outside of the lung (e.g., liver, kidney) - requires vasopressors to maintain blood pressure for covid-19 sub study: 1. subjects requiring invasive mechanical, bi-pap or cpap ventilation at randomization. 2. subjects receiving any other investigational or empiric treatment for sars-2-cov (either as part of a clinical trial or under emergency approval (approved agents for the management of symptoms, e.g., fever, are permitted). 3. subjects who are known hiv-positive (and not undetectable at most recent hiv rna assessment) 4. subjects who are currently taking immunomodulating biologics (e.g, interferons, interleukin) 5. subjects with severe sepsis due to either their sars-cov-2 infection or a concurrent viral, bacterial, or fungal infection and meeting at least one of the following criteria: - have evidence of vital organ failure outside of the lung (e.g., liver, kidney) - require vasopressors to maintain blood pressure 6. subjects meeting exclusion criteria #2, 3, 5 and 6 of the main study

1. subjects may not be on hospice care or, in the opinion of the investigator, have a low chance of survival during the first 10 days of treatment 2. subjects with alanine aminotransferase (alt), aspartate aminotransferase (ast), or alkaline phosphatase (alp) ≥3x uln and total bilirubin (tbili) ≥2x uln note: subjects with alt/ast/alp ≥ 3x uln and tb ≥2x uln that have been chronically stable (for >1 year on more than one assessments) due to known liver pathology including malignancy (primary or metastasis), chronic medications, transplantation, or chronic infection will not be excluded 3. female subjects breastfeeding or planning to breastfeed at any time through 30 days after the last dose of study drug 4. subjects taking any other investigational drug used to treat pulmonary infection. 5. psychiatric or cognitive illness or recreational drug/alcohol use that, in the opinion of the principal investigator, would affect subject safety and/or compliance 6. subjects with known hypersensitivity to das181 and/or any of its components 7. subjects with severe sepsis due to either their baseline sad-rv infection or a concurrent viral, bacterial, or fungal infection and meet at least one of the following criteria: - has evidence of vital organ failure outside of the lung (e.g., liver, kidney) - requires vasopressors to maintain blood pressure for covid-19 sub study: 1. subjects requiring invasive mechanical, bi-pap or cpap ventilation at randomization. 2. subjects receiving any other investigational or empiric treatment for sars-2-cov (either as part of a clinical trial or under emergency approval (approved agents for the management of symptoms, e.g., fever, are permitted). 3. subjects who are known hiv-positive (and not undetectable at most recent hiv rna assessment) 4. subjects who are currently taking immunomodulating biologics (e.g, interferons, interleukin) 5. subjects with severe sepsis due to either their sars-cov-2 infection or a concurrent viral, bacterial, or fungal infection and meeting at least one of the following criteria: - have evidence of vital organ failure outside of the lung (e.g., liver, kidney) - require vasopressors to maintain blood pressure 6. subjects meeting exclusion criteria #2, 3, 5 and 6 of the main study