A potential subject who meets any of the following criteria will be excluded from participation in this study:1. Accompanying diseases other than COVID-19 with an expected survival time of less than 6 months2. Chronic severe pulmonary dysfunction like obstructive lung disease (COPD), Gold stage 4, severe emphysema, or lung fibrosis with usual interstitial pneumonia (IUP) pattern 3. Chronic heart failure NYHA >= 3 and/or pre-existing reduction of left ventricular ejection fraction to = 30% for which among others e.g. strict fluid restriction is needed 4. Clinical diagnosis of circulatory overload for which active therapy (like increased doses of diuretics) is initiated 5. Clinical judgement of deterioration in oxygenation (e.g. more than 2 L increase in additonal O2 by nose tube), respiratory rates ( e.g. more than 5 / min increase) in the 2 hours before the planned randomisation / plasma infusion 6. Signs of severe coagulopathy : thrombocytopenia by consumption ( <100 x 10e9/l) or prolongation of the PT (+3 sec) , PTT (+ 5 sec) 7. Any history of severe adverse reactions to plasma proteins8. Known deficiency of immunoglobulin A9. Pregnancy10. Breastfeeding women11. Psychiatric or cognitive illness or recreational drug/alcohol use that in the opinion of the principal investigator, would affect subject safety and/or compliance

A potential subject who meets any of the following criteria will be excluded from participation in this study:1. Accompanying diseases other than COVID-19 with an expected survival time of less than 6 months2. Chronic severe pulmonary dysfunction like obstructive lung disease (COPD), Gold stage 4, severe emphysema, or lung fibrosis with usual interstitial pneumonia (IUP) pattern 3. Chronic heart failure NYHA >= 3 and/or pre-existing reduction of left ventricular ejection fraction to = 30% for which among others e.g. strict fluid restriction is needed 4. Clinical diagnosis of circulatory overload for which active therapy (like increased doses of diuretics) is initiated 5. Clinical judgement of deterioration in oxygenation (e.g. more than 2 L increase in additonal O2 by nose tube), respiratory rates ( e.g. more than 5 / min increase) in the 2 hours before the planned randomisation / plasma infusion 6. Signs of severe coagulopathy : thrombocytopenia by consumption ( <100 x 10e9/l) or prolongation of the PT (+3 sec) , PTT (+ 5 sec) 7. Any history of severe adverse reactions to plasma proteins8. Known deficiency of immunoglobulin A9. Pregnancy10. Breastfeeding women11. Psychiatric or cognitive illness or recreational drug/alcohol use that in the opinion of the principal investigator, would affect subject safety and/or compliance