* have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (\<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 * require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 * have known allergies to any of the components used in the formulation of the interventions * have hemodynamic instability requiring use of pressors within 24 hours of randomization * suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention * have any co-morbidity requiring surgery within \<7 days, or that is considered life-threatening within 29 days * have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study * have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study * have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing * have received treatment with a sars-cov-2 specific monoclonal antibody * have received convalescent covid-19 plasma treatment * have participated in a previous sars-cov-2 vaccine study or have received a sars-cov-2 vaccine * have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed * are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study * mothers who are breast feeding participants in treatment arm 22 only * have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator * are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable. participants in treatment arm 23 only * spo2 ≤ 93% on room air at sea level, or while on chronic oxygen therapy and/or respiratory support due to underlying non-covid-19 related comorbidity, respiratory rate ≥30 per minute, and heart rate ≥125 per minute due to covid-19 (fda february 2021) * require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 * have known allergies to any of the components used in the formulation of the interventions * have hemodynamic instability requiring use of pressors within 24 hours of randomization * suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention * have any co-morbidity requiring surgery within 7 days, or that is considered life-threatening within 29 days * have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study. * have received treatment with a sars-cov-2 specific monoclonal antibody or remdesivir within 90 days before dosing. * have received convalescent covid-19 plasma treatment within 90 days before dosing * have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed * are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study * are currently pregnant or breast feeding

* have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (\<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 * require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 * have known allergies to any of the components used in the formulation of the interventions * have hemodynamic instability requiring use of pressors within 24 hours of randomization * suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention * have any co-morbidity requiring surgery within \<7 days, or that is considered life-threatening within 29 days * have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study * have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study * have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing * have received treatment with a sars-cov-2 specific monoclonal antibody * have received convalescent covid-19 plasma treatment * have participated in a previous sars-cov-2 vaccine study or have received a sars-cov-2 vaccine * have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed * are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study * mothers who are breast feeding participants in treatment arm 22 only * have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator * are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable. participants in treatment arm 23 only * spo2 ≤ 93% on room air at sea level, or while on chronic oxygen therapy and/or respiratory support due to underlying non-covid-19 related comorbidity, respiratory rate ≥30 per minute, and heart rate ≥125 per minute due to covid-19 (fda february 2021) * require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 * have known allergies to any of the components used in the formulation of the interventions * have hemodynamic instability requiring use of pressors within 24 hours of randomization * suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention * have any co-morbidity requiring surgery within 7 days, or that is considered life-threatening within 29 days * have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study. * have received treatment with a sars-cov-2 specific monoclonal antibody or remdesivir within 90 days before dosing. * have received convalescent covid-19 plasma treatment within 90 days before dosing * have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed * are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study * are currently pregnant or breast feeding

have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 have known allergies to any of the components used in the formulation of the interventions have hemodynamic instability requiring use of pressors within 24 hours of randomization suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing have received treatment with a sars-cov-2 specific monoclonal antibody have received convalescent covid-19 plasma treatment have participated in a previous sars-cov-2 vaccine study or have received a sars-cov-2 vaccine have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study mothers who are breast feeding participants in treatment arm 22 only have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable. participants in treatment arm 23 only spo2 ≤ 93% on room air at sea level, or while on chronic oxygen therapy and/or respiratory support due to underlying non-covid-19 related comorbidity, respiratory rate ≥30 per minute, and heart rate ≥125 per minute due to covid-19 (fda february 2021) require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 have known allergies to any of the components used in the formulation of the interventions have hemodynamic instability requiring use of pressors within 24 hours of randomization suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention have any co-morbidity requiring surgery within 7 days, or that is considered life-threatening within 29 days have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study. have received treatment with a sars-cov-2 specific monoclonal antibody or remdesivir within 90 days before dosing. have received convalescent covid-19 plasma treatment within 90 days before dosing have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study are currently pregnant or breast feeding

have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 have known allergies to any of the components used in the formulation of the interventions have hemodynamic instability requiring use of pressors within 24 hours of randomization suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing have received treatment with a sars-cov-2 specific monoclonal antibody have received convalescent covid-19 plasma treatment have participated in a previous sars-cov-2 vaccine study or have received a sars-cov-2 vaccine have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study mothers who are breast feeding participants in treatment arm 22 only have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable. participants in treatment arm 23 only spo2 ≤ 93% on room air at sea level, or while on chronic oxygen therapy and/or respiratory support due to underlying non-covid-19 related comorbidity, respiratory rate ≥30 per minute, and heart rate ≥125 per minute due to covid-19 (fda february 2021) require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 have known allergies to any of the components used in the formulation of the interventions have hemodynamic instability requiring use of pressors within 24 hours of randomization suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention have any co-morbidity requiring surgery within 7 days, or that is considered life-threatening within 29 days have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study. have received treatment with a sars-cov-2 specific monoclonal antibody or remdesivir within 90 days before dosing. have received convalescent covid-19 plasma treatment within 90 days before dosing have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study are currently pregnant or breast feeding

have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 have known allergies to any of the components used in the formulation of the interventions have hemodynamic instability requiring use of pressors within 24 hours of randomization suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing have received treatment with a sars-cov-2 specific monoclonal antibody have received convalescent covid-19 plasma treatment have participated in a previous sars-cov-2 vaccine study or have received a sars-cov-2 vaccine have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study mothers who are breast feeding participants in treatment arm 22 only have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable.

have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 have known allergies to any of the components used in the formulation of the interventions have hemodynamic instability requiring use of pressors within 24 hours of randomization suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing have received treatment with a sars-cov-2 specific monoclonal antibody have received convalescent covid-19 plasma treatment have participated in a previous sars-cov-2 vaccine study or have received a sars-cov-2 vaccine have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study mothers who are breast feeding participants in treatment arm 22 only have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable.

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 - require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have received convalescent covid-19 plasma treatment - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - mothers who are breast feeding participants in treatment arm 22 only - have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator - are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable.

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute due to covid-19 - require mechanical ventilation or anticipated impending need for mechanical ventilation due to covid-19 - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have received convalescent covid-19 plasma treatment - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - mothers who are breast feeding participants in treatment arm 22 only - have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator - are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable.

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are breast feeding - have body weight <40 kilograms (kg) participants in treatment arm 15 only - have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator - are 12-17 years of age (inclusive) and - have at least 1 risk factor for developing severe covid-19 at screening, or - are ≥40 kg - are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable.

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are breast feeding - have body weight <40 kilograms (kg) participants in treatment arm 15 only - have a diagnosis of multisystem inflammatory syndrome in children (mis-c) in the opinion of the investigator - are 12-17 years of age (inclusive) and - have at least 1 risk factor for developing severe covid-19 at screening, or - are ≥40 kg - are currently hospitalized for treatment of covid-19. other reasons for hospitalization are acceptable.

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are breast feeding - have body weight <40 kilograms (kg)

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are breast feeding - have body weight <40 kilograms (kg)

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated in a previous sars-cov-2 vaccine study - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are pregnant or breast feeding - have body weight <40 kilograms (kg)

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated in a previous sars-cov-2 vaccine study - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are pregnant or breast feeding - have body weight <40 kilograms (kg)

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated in a previous sars-cov-2 vaccine study - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are pregnant or breast feeding

- have oxygen saturation (spo2) less than or equal to (≤)93 percent (%) on room air at sea level or ratio of arterial oxygen partial pressure (pao2 in millimeters of mercury) to fractional inspired oxygen (fio2) less than (<)300, respiratory rate greater than or equal to (≥)30 per minute, heart rate ≥125 per minute - require mechanical ventilation or anticipated impending need for mechanical ventilation - have known allergies to any of the components used in the formulation of the interventions - have hemodynamic instability requiring use of pressors within 24 hours of randomization - suspected or proven serious, active bacterial, fungal, viral, or other infection (besides covid-19) that in the opinion of the investigator could constitute a risk when taking intervention - have any co-morbidity requiring surgery within <7 days, or that is considered life-threatening within 29 days - have any serious concomitant systemic disease, condition or disorder that, in the opinion of the investigator, should preclude participation in this study - have a history of a positive sars-cov-2 test prior to the one serving as eligibility for this study - have received an investigational intervention for sars-cov-2 prophylaxis within 30 days before dosing - have received treatment with a sars-cov-2 specific monoclonal antibody - have a history of convalescent covid-19 plasma treatment - have participated in a previous sars-cov-2 vaccine study - have participated, within the last 30 days, in a clinical study involving an investigational intervention. if the previous investigational intervention has a long half-life, 5 half-lives or 30 days, whichever is longer, should have passed - are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study - are pregnant or breast feeding