inclusion criteria: * recent (≥6 days and ≤16 days of flu-like symptoms or malaise prior to randomization) infection with covid-19. * covid-19 diagnosis confirmed by antigen detection test and/or pcr and/or positive serology, or any emerging and validated diagnostic laboratory test for covid-19 within this period. for patients with a negative sars-cov-2 pcr and either a positive sars-cov-2 antigen or antibody test, the presence of suggestive lesions for covid-19 on chest-ct scan is mandatory. * in some patients, it may be impossible to get a confident laboratory confirmation of covid-19 diagnosis after 24h of hospital admission because viral load is low and/or problems with diagnostic sensitivity. in those cases, in absence of an alternative diagnosis, and with highly suspect bilateral ground glass opacities on recent (\<24h) chest-ct scan (confirmed by a radiologist and pulmonary physician as probable covid-19), and a typical clinical and chemical diagnosis with signs of cytokine release syndrome, a patient can be enrolled as probable sars-cov-2-infected. in all cases, this needs confirmation by later seroconversion. * presence of hypoxia defined as : * o2 saturation below 93% on minimal 2l/min o2 therapy; and/or * pao2/fio2 below 350 mmhg (strongly recommended: patient in upright position, after minimal 3 minutes without supplemental oxygen; in ventilated patients or ecmo patients pao2 can be taken from invasive arterial line and fio2 taken directly from mechanical ventilation settings). * signs of acute lung injury and/or cytokine release syndrome defined as any of the following * serum ferritin concentration \>1000 mcg/l and rising since last 24h * single ferritin above 2000 mcg/l in patients requiring immediate high flow oxygen device (optiflow) or non-invasive or invasive mechanical ventilation * lymphopenia defined as \<800 lymphocytes/microliter and two of the following extra criteria * ferritin \> 700 mcg/l and rising since last 24h * increased ldh (above 300 iu/l) and rising since last 24h * d-dimers \> 1000 ng/ml and rising since last 24h * crp above 70 mg/l and rising since last 24h and absence of bacterial infection * if three of the above are present at admission, no need to document 24h rise * low dose chest ct or hrct or angio chest ct scan showing bilateral infiltrates within last 2 days prior to randomisation * admitted to specialized covid-19 ward or an icu ward taking care of covid-19 patients * age ≥ 18 years * women of childbearing potential must have a negative serum pregnancy test pre-dose on day 1. women of childbearing potential must consistently and correctly use (during the entire treatment period and 4weeks after last zilucoplan® administration ) at least 1 highly effective method for contraception. * willing and able to provide informed consent or legal representative willing to provide informed consent

inclusion criteria: * recent (≥6 days and ≤16 days of flu-like symptoms or malaise prior to randomization) infection with covid-19. * covid-19 diagnosis confirmed by antigen detection test and/or pcr and/or positive serology, or any emerging and validated diagnostic laboratory test for covid-19 within this period. for patients with a negative sars-cov-2 pcr and either a positive sars-cov-2 antigen or antibody test, the presence of suggestive lesions for covid-19 on chest-ct scan is mandatory. * in some patients, it may be impossible to get a confident laboratory confirmation of covid-19 diagnosis after 24h of hospital admission because viral load is low and/or problems with diagnostic sensitivity. in those cases, in absence of an alternative diagnosis, and with highly suspect bilateral ground glass opacities on recent (\<24h) chest-ct scan (confirmed by a radiologist and pulmonary physician as probable covid-19), and a typical clinical and chemical diagnosis with signs of cytokine release syndrome, a patient can be enrolled as probable sars-cov-2-infected. in all cases, this needs confirmation by later seroconversion. * presence of hypoxia defined as : * o2 saturation below 93% on minimal 2l/min o2 therapy; and/or * pao2/fio2 below 350 mmhg (strongly recommended: patient in upright position, after minimal 3 minutes without supplemental oxygen; in ventilated patients or ecmo patients pao2 can be taken from invasive arterial line and fio2 taken directly from mechanical ventilation settings). * signs of acute lung injury and/or cytokine release syndrome defined as any of the following * serum ferritin concentration \>1000 mcg/l and rising since last 24h * single ferritin above 2000 mcg/l in patients requiring immediate high flow oxygen device (optiflow) or non-invasive or invasive mechanical ventilation * lymphopenia defined as \<800 lymphocytes/microliter and two of the following extra criteria * ferritin \> 700 mcg/l and rising since last 24h * increased ldh (above 300 iu/l) and rising since last 24h * d-dimers \> 1000 ng/ml and rising since last 24h * crp above 70 mg/l and rising since last 24h and absence of bacterial infection * if three of the above are present at admission, no need to document 24h rise * low dose chest ct or hrct or angio chest ct scan showing bilateral infiltrates within last 2 days prior to randomisation * admitted to specialized covid-19 ward or an icu ward taking care of covid-19 patients * age ≥ 18 years * women of childbearing potential must have a negative serum pregnancy test pre-dose on day 1. women of childbearing potential must consistently and correctly use (during the entire treatment period and 4weeks after last zilucoplan® administration ) at least 1 highly effective method for contraception. * willing and able to provide informed consent or legal representative willing to provide informed consent

inclusion criteria: - recent (≥6 days and ≤16 days of flu-like symptoms or malaise prior to randomization) infection with covid-19. - covid-19 diagnosis confirmed by antigen detection test and/or pcr and/or positive serology, or any emerging and validated diagnostic laboratory test for covid-19 within this period. for patients with a negative sars-cov-2 pcr and either a positive sars-cov-2 antigen or antibody test, the presence of suggestive lesions for covid-19 on chest-ct scan is mandatory. - in some patients, it may be impossible to get a confident laboratory confirmation of covid-19 diagnosis after 24h of hospital admission because viral load is low and/or problems with diagnostic sensitivity. in those cases, in absence of an alternative diagnosis, and with highly suspect bilateral ground glass opacities on recent (<24h) chest-ct scan (confirmed by a radiologist and pulmonary physician as probable covid-19), and a typical clinical and chemical diagnosis with signs of cytokine release syndrome, a patient can be enrolled as probable sars-cov-2-infected. in all cases, this needs confirmation by later seroconversion. - presence of hypoxia defined as : - o2 saturation below 93% on minimal 2l/min o2 therapy; and/or - pao2/fio2 below 350 mmhg (strongly recommended: patient in upright position, after minimal 3 minutes without supplemental oxygen; in ventilated patients or ecmo patients pao2 can be taken from invasive arterial line and fio2 taken directly from mechanical ventilation settings). - signs of acute lung injury and/or cytokine release syndrome defined as any of the following - serum ferritin concentration >1000 mcg/l and rising since last 24h - single ferritin above 2000 mcg/l in patients requiring immediate high flow oxygen device (optiflow) or non-invasive or invasive mechanical ventilation - lymphopenia defined as <800 lymphocytes/microliter and two of the following extra criteria - ferritin > 700 mcg/l and rising since last 24h - increased ldh (above 300 iu/l) and rising since last 24h - d-dimers > 1000 ng/ml and rising since last 24h - crp above 70 mg/l and rising since last 24h and absence of bacterial infection - if three of the above are present at admission, no need to document 24h rise - low dose chest ct or hrct or angio chest ct scan showing bilateral infiltrates within last 2 days prior to randomisation - admitted to specialized covid-19 ward or an icu ward taking care of covid-19 patients - age ≥ 18 years - women of childbearing potential must have a negative serum pregnancy test pre-dose on day 1. women of childbearing potential must consistently and correctly use (during the entire treatment period and 4weeks after last zilucoplan® administration ) at least 1 highly effective method for contraception. - willing and able to provide informed consent or legal representative willing to provide informed consent

inclusion criteria: - recent (≥6 days and ≤16 days of flu-like symptoms or malaise prior to randomization) infection with covid-19. - covid-19 diagnosis confirmed by antigen detection test and/or pcr and/or positive serology, or any emerging and validated diagnostic laboratory test for covid-19 within this period. for patients with a negative sars-cov-2 pcr and either a positive sars-cov-2 antigen or antibody test, the presence of suggestive lesions for covid-19 on chest-ct scan is mandatory. - in some patients, it may be impossible to get a confident laboratory confirmation of covid-19 diagnosis after 24h of hospital admission because viral load is low and/or problems with diagnostic sensitivity. in those cases, in absence of an alternative diagnosis, and with highly suspect bilateral ground glass opacities on recent (<24h) chest-ct scan (confirmed by a radiologist and pulmonary physician as probable covid-19), and a typical clinical and chemical diagnosis with signs of cytokine release syndrome, a patient can be enrolled as probable sars-cov-2-infected. in all cases, this needs confirmation by later seroconversion. - presence of hypoxia defined as : - o2 saturation below 93% on minimal 2l/min o2 therapy; and/or - pao2/fio2 below 350 mmhg (strongly recommended: patient in upright position, after minimal 3 minutes without supplemental oxygen; in ventilated patients or ecmo patients pao2 can be taken from invasive arterial line and fio2 taken directly from mechanical ventilation settings). - signs of acute lung injury and/or cytokine release syndrome defined as any of the following - serum ferritin concentration >1000 mcg/l and rising since last 24h - single ferritin above 2000 mcg/l in patients requiring immediate high flow oxygen device (optiflow) or non-invasive or invasive mechanical ventilation - lymphopenia defined as <800 lymphocytes/microliter and two of the following extra criteria - ferritin > 700 mcg/l and rising since last 24h - increased ldh (above 300 iu/l) and rising since last 24h - d-dimers > 1000 ng/ml and rising since last 24h - crp above 70 mg/l and rising since last 24h and absence of bacterial infection - if three of the above are present at admission, no need to document 24h rise - low dose chest ct or hrct or angio chest ct scan showing bilateral infiltrates within last 2 days prior to randomisation - admitted to specialized covid-19 ward or an icu ward taking care of covid-19 patients - age ≥ 18 years - women of childbearing potential must have a negative serum pregnancy test pre-dose on day 1. women of childbearing potential must consistently and correctly use (during the entire treatment period and 4weeks after last zilucoplan® administration ) at least 1 highly effective method for contraception. - willing and able to provide informed consent or legal representative willing to provide informed consent

inclusion criteria: - recent (≥6 days and ≤16 days of flu-like symptoms or malaise prior to randomization) infection with covid-19. - covid-19 diagnosis confirmed by antigen detection test and/or pcr and/or positive serology, or any emerging and validated diagnostic laboratory test for covid-19 within this period. for patients with a negative sars-cov-2 pcr and either a positive sars-cov-2 antigen or antibody test, the presence of suggestive lesions for covid-19 on chest-ct scan is mandatory. - in some patients, it may be impossible to get a confident laboratory confirmation of covid-19 diagnosis after 24h of hospital admission because viral load is low and/or problems with diagnostic sensitivity. in those cases, in absence of an alternative diagnosis, and with highly suspect bilateral ground glass opacities on recent (<24h) chest-ct scan (confirmed by a radiologist and pulmonary physician as probable covid-19), and a typical clinical and chemical diagnosis with signs of cytokine release syndrome, a patient can be enrolled as probable sars-cov-2-infected. in all cases, this needs confirmation by later seroconversion. - presence of hypoxia defined as : - o2 saturation below 93% on minimal 2l/min o2 therapy; and/or - patient on ecmo or pao2/fio2 below 350 mmhg (strongly recommended: patient in upright position, after minimal 3 minutes without supplemental oxygen; in ventilated patients or ecmo patients pao2 can be taken from invasive arterial line and fio2 taken directly from mechanical ventilation settings). - signs of acute lung injury and/or cytokine release syndrome defined as any of the following - serum ferritin concentration >1000 mcg/l and rising since last 24h - single ferritin above 2000 mcg/l in patients requiring immediate high flow oxygen device (optiflow) or non-invasive or invasive mechanical ventilation - lymphopenia defined as <800 lymphocytes/microliter and two of the following extra criteria - ferritin > 700 mcg/l and rising since last 24h - increased ldh (above 300 iu/l) and rising since last 24h -d-dimers > 1000 ng/ml and rising since last 24h - crp above 70 mg/l and rising since last 24h and absence of bacterial infection - if three of the above are present at admission, no need to document 24h rise - low dose chest ct or hrct or angio chest ct scan showing bilateral infiltrates within last 2 days prior to randomisation - admitted to specialized covid-19 ward or an icu ward taking care of covid-19 patients - age ≥ 18 years - women of childbearing potential must have a negative serum pregnancy test pre-dose on day 1. women of childbearing potential must consistently and correctly use (during the entire treatment period and 4weeks after last zilucoplan® administration ) at least 1 highly effective method for contraception. - willing and able to provide informed consent or legal representative willing to provide informed consent

inclusion criteria: - recent (≥6 days and ≤16 days of flu-like symptoms or malaise prior to randomization) infection with covid-19. - covid-19 diagnosis confirmed by antigen detection test and/or pcr and/or positive serology, or any emerging and validated diagnostic laboratory test for covid-19 within this period. for patients with a negative sars-cov-2 pcr and either a positive sars-cov-2 antigen or antibody test, the presence of suggestive lesions for covid-19 on chest-ct scan is mandatory. - in some patients, it may be impossible to get a confident laboratory confirmation of covid-19 diagnosis after 24h of hospital admission because viral load is low and/or problems with diagnostic sensitivity. in those cases, in absence of an alternative diagnosis, and with highly suspect bilateral ground glass opacities on recent (<24h) chest-ct scan (confirmed by a radiologist and pulmonary physician as probable covid-19), and a typical clinical and chemical diagnosis with signs of cytokine release syndrome, a patient can be enrolled as probable sars-cov-2-infected. in all cases, this needs confirmation by later seroconversion. - presence of hypoxia defined as : - o2 saturation below 93% on minimal 2l/min o2 therapy; and/or - patient on ecmo or pao2/fio2 below 350 mmhg (strongly recommended: patient in upright position, after minimal 3 minutes without supplemental oxygen; in ventilated patients or ecmo patients pao2 can be taken from invasive arterial line and fio2 taken directly from mechanical ventilation settings). - signs of acute lung injury and/or cytokine release syndrome defined as any of the following - serum ferritin concentration >1000 mcg/l and rising since last 24h - single ferritin above 2000 mcg/l in patients requiring immediate high flow oxygen device (optiflow) or non-invasive or invasive mechanical ventilation - lymphopenia defined as <800 lymphocytes/microliter and two of the following extra criteria - ferritin > 700 mcg/l and rising since last 24h - increased ldh (above 300 iu/l) and rising since last 24h -d-dimers > 1000 ng/ml and rising since last 24h - crp above 70 mg/l and rising since last 24h and absence of bacterial infection - if three of the above are present at admission, no need to document 24h rise - low dose chest ct or hrct or angio chest ct scan showing bilateral infiltrates within last 2 days prior to randomisation - admitted to specialized covid-19 ward or an icu ward taking care of covid-19 patients - age ≥ 18 years - women of childbearing potential must have a negative serum pregnancy test pre-dose on day 1. women of childbearing potential must consistently and correctly use (during the entire treatment period and 4weeks after last zilucoplan® administration ) at least 1 highly effective method for contraception. - willing and able to provide informed consent or legal representative willing to provide informed consent