inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: 1. admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. 2. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. 3. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. 4. veteran 18 years of age at time of screening. 5. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)reverse transcription polymerase chain reaction (rt-pcr) or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected \> 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking \> 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: 1. admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. 2. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. 3. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. 4. veteran 18 years of age at time of screening. 5. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)reverse transcription polymerase chain reaction (rt-pcr) or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected \> 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking \> 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. veteran 18 years of age at time of screening. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)reverse transcription polymerase chain reaction (rt-pcr) or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected > 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking > 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. veteran 18 years of age at time of screening. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)reverse transcription polymerase chain reaction (rt-pcr) or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected > 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking > 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. veteran 18 years of age at time of screening. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)rt-pcr or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected > 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking > 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. veteran 18 years of age at time of screening. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)rt-pcr or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected > 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking > 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: 1. admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. 2. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. 3. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. 4. veteran 18 years of age at time of screening. 5. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)rt-pcr or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected > 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking > 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.

inclusion criteria: veterans must meet all of the following criteria to be eligible to participate: 1. admitted to a participating va clinical site with symptoms suggestive of sars-cov-2 infection. 2. participant (or legally authorized representative) provides informed consent prior to initiation of any study procedures. 3. participant (or legally authorized representative) understands and agrees to comply with planned study procedures. 4. veteran 18 years of age at time of screening. 5. has laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) or antigen test, as documented by either of the following: (1)rt-pcr or antigen positive (nasopharyngeal, oropharyngeal, saliva, lower respiratory) in sample collected 72 hours prior to screening; (2)rt-pcr or antigen positive in sample collected > 72 hours but 168 hours (i.e. 7 days) prior to screening, documented inability to obtain a repeat sample (e.g. due to lack of testing supplies, limited testing capacity, results taking > 24 hours, etc.), and progressive disease suggestive of ongoing sars-cov-2 infection. 6.requiring oxygen by nasal cannula or by face-mask as a new treatment (or if previously on home oxygen, at a liter flow at least 2 lpm greater than home prescription), but not on humidified heated high-flow nasal cannula (hhhfnc) at 15 lpm. 7.can be randomized within 72 hours of hospital admission. 8.agrees not to participate in another therapeutic clinical trial for the treatment of covid-19 or sars-cov-2 through day 29 without approval from the investigator(s). taking part in other research studies, including those unrelated to sars-cov-2, without first discussing it with the investigators of this study may invalidate the results of this study, as well as that of the other study.