1. Male or female ≥18 and ≤ 80 years of age 2. Informed consent for participation in the study (refer to section 15 for detailed informed 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* *[Criterion not applicable to the ECMO additional cohort] Additional inclusion criterion for ECMO-cohort: 7. Intubated and artificially ventilated less than 48 hours before the first poractant alfa administration OR 8. Supported with vvECMO less than 48 hours before

1. Male or female ≥18 and ≤ 80 years of age 2. Informed consent for participation in the study (refer to section 15 for detailed informed 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* *[Criterion not applicable to the ECMO additional cohort] Additional inclusion criterion for ECMO-cohort: 7. Intubated and artificially ventilated less than 48 hours before the first poractant alfa administration OR 8. Supported with vvECMO less than 48 hours before