inclusion criteria: * male veterans admitted to a va hospital. * age \> 18 * hospitalized on an acute care ward with a diagnosis of covid-19 contributing to hospitalization. * positive rt-pcr assay for sars-cov-2 on a nasopharyngeal swab sample. * severity of illness of level 3, 4 or 5 on the influenza severity scale (see appendix a) at the time of randomization. * the subject (or legally acceptable representative if applicable) must provide written informed consent for the trial.

inclusion criteria: * male veterans admitted to a va hospital. * age \> 18 * hospitalized on an acute care ward with a diagnosis of covid-19 contributing to hospitalization. * positive rt-pcr assay for sars-cov-2 on a nasopharyngeal swab sample. * severity of illness of level 3, 4 or 5 on the influenza severity scale (see appendix a) at the time of randomization. * the subject (or legally acceptable representative if applicable) must provide written informed consent for the trial.

inclusion criteria: - male veterans admitted to a va hospital. - age > 18 - hospitalized on an acute care ward with a diagnosis of covid-19 contributing to hospitalization. - positive rt-pcr assay for sars-cov-2 on a nasopharyngeal swab sample. - severity of illness of level 3, 4 or 5 on the influenza severity scale (see appendix a) at the time of randomization. - the subject (or legally acceptable representative if applicable) must provide written informed consent for the trial.

inclusion criteria: - male veterans admitted to a va hospital. - age > 18 - hospitalized on an acute care ward with a diagnosis of covid-19 contributing to hospitalization. - positive rt-pcr assay for sars-cov-2 on a nasopharyngeal swab sample. - severity of illness of level 3, 4 or 5 on the influenza severity scale (see appendix a) at the time of randomization. - the subject (or legally acceptable representative if applicable) must provide written informed consent for the trial.

inclusion criteria: - male veterans admitted to a va hospital. - age 18 and 85; patients > 85 can be enrolled if there is no history of chronic obstructive pulmonary disease (copd), asthma, cardiovascular disease, hypertension, diabetes mellitus or active malignancy. - hospitalized on an acute care ward due to covid-19. - positive rt-pcr assay for sars-cov-2 on a nasopharyngeal swab sample. - severity of illness of level 3, 4 or 5 on the influenza severity scale (see appendix a) at the time of randomization. - the subject (or legally acceptable representative if applicable) must provide written informed consent for the trial.

inclusion criteria: - male veterans admitted to a va hospital. - age 18 and 85; patients > 85 can be enrolled if there is no history of chronic obstructive pulmonary disease (copd), asthma, cardiovascular disease, hypertension, diabetes mellitus or active malignancy. - hospitalized on an acute care ward due to covid-19. - positive rt-pcr assay for sars-cov-2 on a nasopharyngeal swab sample. - severity of illness of level 3, 4 or 5 on the influenza severity scale (see appendix a) at the time of randomization. - the subject (or legally acceptable representative if applicable) must provide written informed consent for the trial.