1. refusal to participate expressed by patient or legally authorized representative 2. need for invasive mechanical ventilation and/or ecmo at the time of enrolment 3. spontaneous blood alt/ast levels \> 5 times the upper limit of normal 4. glomerular filtration rate (gfr) \< 15 ml/min or requiring maintenance dialysis 5. pregnancy or breast-feeding 6. anticipated transfer to another hospital, which is not a study site within 72 hours following randomization 7. known history of allergy or reaction to any component of the study drug formulation. 8. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. 9. any prior receipt of investigational or licensed other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19, and for those not vaccinated, expected receipt of vaccine in the 30 days following hospital discharge, according to current recommendation in each country. 10. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

1. refusal to participate expressed by patient or legally authorized representative 2. need for invasive mechanical ventilation and/or ecmo at the time of enrolment 3. spontaneous blood alt/ast levels \> 5 times the upper limit of normal 4. glomerular filtration rate (gfr) \< 15 ml/min or requiring maintenance dialysis 5. pregnancy or breast-feeding 6. anticipated transfer to another hospital, which is not a study site within 72 hours following randomization 7. known history of allergy or reaction to any component of the study drug formulation. 8. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. 9. any prior receipt of investigational or licensed other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19, and for those not vaccinated, expected receipt of vaccine in the 30 days following hospital discharge, according to current recommendation in each country. 10. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

refusal to participate expressed by patient or legally authorized representative need for invasive mechanical ventilation and/or ecmo at the time of enrolment spontaneous blood alt/ast levels > 5 times the upper limit of normal glomerular filtration rate (gfr) < 15 ml/min or requiring maintenance dialysis pregnancy or breast-feeding anticipated transfer to another hospital, which is not a study site within 72 hours following randomization known history of allergy or reaction to any component of the study drug formulation. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. any prior receipt of investigational or licensed other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19, and for those not vaccinated, expected receipt of vaccine in the 30 days following hospital discharge, according to current recommendation in each country. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

refusal to participate expressed by patient or legally authorized representative need for invasive mechanical ventilation and/or ecmo at the time of enrolment spontaneous blood alt/ast levels > 5 times the upper limit of normal glomerular filtration rate (gfr) < 15 ml/min or requiring maintenance dialysis pregnancy or breast-feeding anticipated transfer to another hospital, which is not a study site within 72 hours following randomization known history of allergy or reaction to any component of the study drug formulation. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. any prior receipt of investigational or licensed other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19, and for those not vaccinated, expected receipt of vaccine in the 30 days following hospital discharge, according to current recommendation in each country. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

1. refusal to participate expressed by patient or legally authorized representative 2. need for invasive mechanical ventilation and/or ecmo at the time of enrolment 3. spontaneous blood alt/ast levels > 5 times the upper limit of normal 4. glomerular filtration rate (gfr) < 15 ml/min or requiring maintenance dialysis 5. pregnancy or breast-feeding 6. anticipated transfer to another hospital, which is not a study site within 72 hours following randomization 7. known history of allergy or reaction to any component of the study drug formulation. 8. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. 9. any prior receipt of investigational or licensed other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19, and for those not vaccinated, expected receipt of vaccine in the 30 days following hospital discharge, according to current recommendation in each country. 10. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

1. refusal to participate expressed by patient or legally authorized representative 2. need for invasive mechanical ventilation and/or ecmo at the time of enrolment 3. spontaneous blood alt/ast levels > 5 times the upper limit of normal 4. glomerular filtration rate (gfr) < 15 ml/min or requiring maintenance dialysis 5. pregnancy or breast-feeding 6. anticipated transfer to another hospital, which is not a study site within 72 hours following randomization 7. known history of allergy or reaction to any component of the study drug formulation. 8. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. 9. any prior receipt of investigational or licensed other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19, and for those not vaccinated, expected receipt of vaccine in the 30 days following hospital discharge, according to current recommendation in each country. 10. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

1. refusal to participate expressed by patient or legally authorized representative 2. need for invasive mechanical ventilation and/or ecmo at the time of enrolment 3. spontaneous blood alt/ast levels > 5 times the upper limit of normal 4. glomerular filtration rate (gfr) < 15 ml/min or requiring maintenance dialysis 5. pregnancy or breast-feeding 6. anticipated transfer to another hospital, which is not a study site within 72 hours following randomization 7. known history of allergy or reaction to any component of the study drug formulation. 8. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. 9. any prior receipt of investigational or licensed vaccine or other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19 or expected receipt in the 30 days following hospital discharge, according to current recommendation in each country. 10. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

1. refusal to participate expressed by patient or legally authorized representative 2. need for invasive mechanical ventilation and/or ecmo at the time of enrolment 3. spontaneous blood alt/ast levels > 5 times the upper limit of normal 4. glomerular filtration rate (gfr) < 15 ml/min or requiring maintenance dialysis 5. pregnancy or breast-feeding 6. anticipated transfer to another hospital, which is not a study site within 72 hours following randomization 7. known history of allergy or reaction to any component of the study drug formulation. 8. previous hypersensitivity, infusion-related reaction, or severe adverse reaction following administration of monoclonal or polyclonal antibodies. 9. any prior receipt of investigational or licensed vaccine or other mab/biologic indicated for the prevention of sars-cov-2 infection or covid-19 or expected receipt in the 30 days following hospital discharge, according to current recommendation in each country. 10. any medical condition which, in the judgment of the investigator, could interfere with the interpretation of the trial results or that preludes to protocol adherence.

- refusal to participate expressed by patient or legally authorized representative if they are present - spontaneous blood alt/ast levels > 5 times the upper limit of normal. - stage 4 severe chronic kidney disease or requiring dialysis (i.e. egfr < 30 ml/min) - pregnancy or breast-feeding. - anticipated transfer to another hospital, which is not a study site within 72 hours. - patients previously treated with one of the antivirals evaluated in the trial (i.e. remdesivir, interferon ß-1a, lopinavir/ritonavir, hydroxychloroquine) in the past 29 days - contraindication to any study medication including allergy the following exclusion criteria are non applicable since lopinavir/ritonavir, lopinavir/ritonavir plus interferon ß-1a or hydroxychloroquine arm were stopped: - use of medications that are contraindicated with lopinavir/ritonavir i.e. drugs whose metabolism is highly dependent on the isoform cyp3a with narrow therapeutic range (e.g. amiodarone, colchicine, simvastatine). - use of medications that are contraindicated with hydroxychloroquine: citalopram, escitalopram, hydroxyzine, domperidone, pipéraquine. - human immunodeficiency virus infection under highly active antiretroviral therapy (haart). - history of severe depression or attempted suicide or current suicidal ideation

- refusal to participate expressed by patient or legally authorized representative if they are present - spontaneous blood alt/ast levels > 5 times the upper limit of normal. - stage 4 severe chronic kidney disease or requiring dialysis (i.e. egfr < 30 ml/min) - pregnancy or breast-feeding. - anticipated transfer to another hospital, which is not a study site within 72 hours. - patients previously treated with one of the antivirals evaluated in the trial (i.e. remdesivir, interferon ß-1a, lopinavir/ritonavir, hydroxychloroquine) in the past 29 days - contraindication to any study medication including allergy the following exclusion criteria are non applicable since lopinavir/ritonavir, lopinavir/ritonavir plus interferon ß-1a or hydroxychloroquine arm were stopped: - use of medications that are contraindicated with lopinavir/ritonavir i.e. drugs whose metabolism is highly dependent on the isoform cyp3a with narrow therapeutic range (e.g. amiodarone, colchicine, simvastatine). - use of medications that are contraindicated with hydroxychloroquine: citalopram, escitalopram, hydroxyzine, domperidone, pipéraquine. - human immunodeficiency virus infection under highly active antiretroviral therapy (haart). - history of severe depression or attempted suicide or current suicidal ideation