* chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of imp; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded ( inhaled or topical steroids allowed) * regular (daily), systemic administration of corticosteroids at the time on inclusion (inhaled or topical corticosteroids are allowed) * any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (hiv) infection. * pregnancy or lactation. * alcohol or drug abuse. * suspected non-compliance. * presence of vte, including pulmonary embolism or other manifestations of thrombosis * use of any investigational drug (other than hydroxychloroquine) or vaccine within 30 days prior to first dose of study vaccine or planned use during study period. * any clinically significant history of known or suspected anaphylaxis or hypersensitivity reaction as judged by investigator. * known immunoglobulin a (iga) deficiency * existing treatment limitations: do-not-resuscitate (dnr) order or withholding treatment in icu * any other criteria which, as judged by investigator, might compromise a patient's well-being or ability to participate in the study or its outcome. * active malignant disease * cp not available for patients blood type * patient cannot assign written consent * no personnel available for cp of placebo transfusion

* chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of imp; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded ( inhaled or topical steroids allowed) * regular (daily), systemic administration of corticosteroids at the time on inclusion (inhaled or topical corticosteroids are allowed) * any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (hiv) infection. * pregnancy or lactation. * alcohol or drug abuse. * suspected non-compliance. * presence of vte, including pulmonary embolism or other manifestations of thrombosis * use of any investigational drug (other than hydroxychloroquine) or vaccine within 30 days prior to first dose of study vaccine or planned use during study period. * any clinically significant history of known or suspected anaphylaxis or hypersensitivity reaction as judged by investigator. * known immunoglobulin a (iga) deficiency * existing treatment limitations: do-not-resuscitate (dnr) order or withholding treatment in icu * any other criteria which, as judged by investigator, might compromise a patient's well-being or ability to participate in the study or its outcome. * active malignant disease * cp not available for patients blood type * patient cannot assign written consent * no personnel available for cp of placebo transfusion

- chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of imp; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded ( inhaled or topical steroids allowed) - regular (daily), systemic administration of corticosteroids at the time on inclusion (inhaled or topical corticosteroids are allowed) - any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (hiv) infection. - pregnancy or lactation. - alcohol or drug abuse. - suspected non-compliance. - presence of vte, including pulmonary embolism or other manifestations of thrombosis - use of any investigational drug (other than hydroxychloroquine) or vaccine within 30 days prior to first dose of study vaccine or planned use during study period. - any clinically significant history of known or suspected anaphylaxis or hypersensitivity reaction as judged by investigator. - known immunoglobulin a (iga) deficiency - existing treatment limitations: do-not-resuscitate (dnr) order or withholding treatment in icu - any other criteria which, as judged by investigator, might compromise a patient's well-being or ability to participate in the study or its outcome. - active malignant disease - cp not available for patients blood type - patient cannot assign written consent - no personnel available for cp of placebo transfusion

- chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of imp; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded ( inhaled or topical steroids allowed) - regular (daily), systemic administration of corticosteroids at the time on inclusion (inhaled or topical corticosteroids are allowed) - any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (hiv) infection. - pregnancy or lactation. - alcohol or drug abuse. - suspected non-compliance. - presence of vte, including pulmonary embolism or other manifestations of thrombosis - use of any investigational drug (other than hydroxychloroquine) or vaccine within 30 days prior to first dose of study vaccine or planned use during study period. - any clinically significant history of known or suspected anaphylaxis or hypersensitivity reaction as judged by investigator. - known immunoglobulin a (iga) deficiency - existing treatment limitations: do-not-resuscitate (dnr) order or withholding treatment in icu - any other criteria which, as judged by investigator, might compromise a patient's well-being or ability to participate in the study or its outcome. - active malignant disease - cp not available for patients blood type - patient cannot assign written consent - no personnel available for cp of placebo transfusion

- chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of imp; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded ( inhaled or topical steroids allowed) - regular (daily), systemic administration of corticosteroids at the time on inclusion (inhaled or topical corticosteroids are allowed) - any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (hiv) infection. - pregnancy or lactation. - alcohol or drug abuse. - suspected non-compliance. - presence of vte, including pulmonary embolism or other manifestations of thrombosis - use of any investigational drug (other than hydroxychloroquine) or vaccine within 30 days prior to first dose of study vaccine or planned use during study period. - any clinically significant history of known or suspected anaphylaxis or hypersensitivity reaction as judged by investigator. - known immunoglobulin a (iga) deficiency - existing treatment limitations: do-not-resuscitate (dnr) order or withholding treatment in icu - any other criteria which, as judged by investigator, might compromise a patient's well-being or ability to participate in the study or its outcome.

- chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of imp; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded ( inhaled or topical steroids allowed) - regular (daily), systemic administration of corticosteroids at the time on inclusion (inhaled or topical corticosteroids are allowed) - any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (hiv) infection. - pregnancy or lactation. - alcohol or drug abuse. - suspected non-compliance. - presence of vte, including pulmonary embolism or other manifestations of thrombosis - use of any investigational drug (other than hydroxychloroquine) or vaccine within 30 days prior to first dose of study vaccine or planned use during study period. - any clinically significant history of known or suspected anaphylaxis or hypersensitivity reaction as judged by investigator. - known immunoglobulin a (iga) deficiency - existing treatment limitations: do-not-resuscitate (dnr) order or withholding treatment in icu - any other criteria which, as judged by investigator, might compromise a patient's well-being or ability to participate in the study or its outcome.