inclusion criteria: participants were eligible to be included in the study if the following criteria apply: 1. male or female ≥18 and ≤ 80 years of age 2. informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) 3. positive 2019-ncov reverse transcription polymerase chain reaction (rt-pcr) before randomisation 4. arterial partial pressure of oxygen/fraction of inspired oxygen (pao2/fio2) ratio \< 150 mmhg 5. lung compliance ≤45 ml/cmh20 6. intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants were eligible to be included in the study if the following criteria apply: 1. male or female ≥18 and ≤ 80 years of age 2. informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) 3. positive 2019-ncov reverse transcription polymerase chain reaction (rt-pcr) before randomisation 4. arterial partial pressure of oxygen/fraction of inspired oxygen (pao2/fio2) ratio \< 150 mmhg 5. lung compliance ≤45 ml/cmh20 6. intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants were eligible to be included in the study if the following criteria apply: male or female ≥18 and ≤ 80 years of age informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) positive 2019-ncov reverse transcription polymerase chain reaction (rt-pcr) before randomisation arterial partial pressure of oxygen/fraction of inspired oxygen (pao2/fio2) ratio < 150 mmhg lung compliance ≤45 ml/cmh20 intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants were eligible to be included in the study if the following criteria apply: male or female ≥18 and ≤ 80 years of age informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) positive 2019-ncov reverse transcription polymerase chain reaction (rt-pcr) before randomisation arterial partial pressure of oxygen/fraction of inspired oxygen (pao2/fio2) ratio < 150 mmhg lung compliance ≤45 ml/cmh20 intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants are eligible to be included in the study if the following criteria apply: male or female ≥18 and ≤ 80 years of age informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) positive 2019-ncov rt-pcr before randomisation pao2/fio2 ratio < 150 mmhg lung compliance ≤45 ml/cmh20 intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants are eligible to be included in the study if the following criteria apply: male or female ≥18 and ≤ 80 years of age informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) positive 2019-ncov rt-pcr before randomisation pao2/fio2 ratio < 150 mmhg lung compliance ≤45 ml/cmh20 intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants are eligible to be included in the study if the following criteria apply: 1. male or female ≥18 and ≤ 80 years of age 2. informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) 3. positive 2019-ncov rt-pcr before randomisation 4. pao2/fio2 ratio < 150 mmhg 5. lung compliance ≤45 ml/cmh20 6. intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants are eligible to be included in the study if the following criteria apply: 1. male or female ≥18 and ≤ 80 years of age 2. informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) 3. positive 2019-ncov rt-pcr before randomisation 4. pao2/fio2 ratio < 150 mmhg 5. lung compliance ≤45 ml/cmh20 6. intubated and artificially ventilated less than 48 hours before the first poractant alfa administration

inclusion criteria: participants are eligible to be included in the study if the following criteria apply: 1. male or female ≥18 and ≤ 80 years of age 2. informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) 3. positive 2019-ncov rt-pcr before randomisation 4. pao2/fio2 ratio < 150 mmhg 5. lung compliance ≤45 ml/cmh20 6. intubated and artificially ventilated less than 48 hours before the first poractant alfa administration additional inclusion criterion for ecmo-cohort: 7. supported with vvecmo less than 48 hours before the first poractant alfa administration - for the ecmo-cohort substudy cohort only

inclusion criteria: participants are eligible to be included in the study if the following criteria apply: 1. male or female ≥18 and ≤ 80 years of age 2. informed consent for participation in the study (refer to section 15 for detailed inform consent procedure) 3. positive 2019-ncov rt-pcr before randomisation 4. pao2/fio2 ratio < 150 mmhg 5. lung compliance ≤45 ml/cmh20 6. intubated and artificially ventilated less than 48 hours before the first poractant alfa administration additional inclusion criterion for ecmo-cohort: 7. supported with vvecmo less than 48 hours before the first poractant alfa administration - for the ecmo-cohort substudy cohort only