Inclusion Criteria:  A) Proven Sars-CoV-2 by PCR and hospitalization for COVID-19 in combination with either (1) or (2):  Age ≥50  AND (at least one):  Pre-existing cardiovascular disease Diabetic disease Immunodeficiency/immunosuppression Neoplastic disease COPD or chronic liver disease or chronic renal failure Age ≥18  AND (at least one):  SpO2 ≤ 94% on room air or requiring supplemental oxygen at screening Typical changes on chest x-ray and/or lung-CT scan Immunosuppression or neoplastic disease  B) Informed Consent as documented by signature (Appendix Informed Consent Form) of the patient or, in case of inability, of the next relative/care-taking person. In the latter case, an independent doctor will also be involved and her/his signature will be required in order to enrol the patient.  Exclusion Criteria:  Contraindications to the class of drugs under study, e.g. known hypersensitivity or allergy to class of drugs or the investigational product (FFP) Known IgA deficiency Cytokine Release Syndrome grade ≥3 (see score)* ARDS Patients already hospitalized in intensive care unit and/or already receiving mechanical ventilation Known or suspected non-compliance, drug or alcohol abuse Previous enrolment into the current study Enrolment of the investigator, his/her family members, employees and other dependent persons Women who are pregnant or breast feeding Intention to become pregnant during the course of the study Lack of safe contraception, defined as: Female participants of childbearing potential, not using and not willing to continue using a medically reliable method of contraception for the entire study duration, such as oral, injectable, or implantable contraceptives, or intrauterine contraceptive devices, or who are not using any other method considered sufficiently reliable by the investigator in individual cases. Please note that female participants who are surgically sterilised / hysterectomised or post-menopausal for longer than 2 years are not considered as being of child bearing potential