cohort 1: elderly and high covid-age population: inclusion criteria: * sars-cov-2 rna detected in a specimen, ≤ 7 days after onset of symptoms * symptoms of covid-19 (so including but not limited to: fever; cough; breathlessness; chest pain; wheeze; sore throat; haemoptysis; runny nose; fatigue; muscle or joint pain; confusion; headache; seizures; nausea; vomiting; diarrhoea; abdominal pain; poor appetite; skin ulcers or rash; ear pain; conjunctivitis; anosmia; bleeding; lymphadenopathy. the attending clinician will determine if symptoms are consistent with covid-19. * clinical status not requiring admission to hospital for covid-19 disease and oxygen support * ability to transfuse (per randomisation) within 7 days after onset of symptoms * men or women, 70 years or older or * under 70 years with significant comorbidities (arterial hypertension, diabetes, obesity, asthma or other chronic pulmonary disease, cardiovascular disease, cerebrovascular disease, chronic kidney disease / dialysis, hemoglobinopathies, liver disease, chronic neurological disease, rheumatoid arthritis, lupus or psoriasis) resulting in a 'covid-age' of 70 years or more according to the alama risk calculator https://alama.org.uk/covid-19-medical-risk-assessment/

cohort 1: elderly and high covid-age population: inclusion criteria: * sars-cov-2 rna detected in a specimen, ≤ 7 days after onset of symptoms * symptoms of covid-19 (so including but not limited to: fever; cough; breathlessness; chest pain; wheeze; sore throat; haemoptysis; runny nose; fatigue; muscle or joint pain; confusion; headache; seizures; nausea; vomiting; diarrhoea; abdominal pain; poor appetite; skin ulcers or rash; ear pain; conjunctivitis; anosmia; bleeding; lymphadenopathy. the attending clinician will determine if symptoms are consistent with covid-19. * clinical status not requiring admission to hospital for covid-19 disease and oxygen support * ability to transfuse (per randomisation) within 7 days after onset of symptoms * men or women, 70 years or older or * under 70 years with significant comorbidities (arterial hypertension, diabetes, obesity, asthma or other chronic pulmonary disease, cardiovascular disease, cerebrovascular disease, chronic kidney disease / dialysis, hemoglobinopathies, liver disease, chronic neurological disease, rheumatoid arthritis, lupus or psoriasis) resulting in a 'covid-age' of 70 years or more according to the alama risk calculator https://alama.org.uk/covid-19-medical-risk-assessment/

cohort 1: elderly and high covid-age population: inclusion criteria: sars-cov-2 rna detected in a specimen, ≤ 7 days after onset of symptoms symptoms of covid-19 (so including but not limited to: fever; cough; breathlessness; chest pain; wheeze; sore throat; haemoptysis; runny nose; fatigue; muscle or joint pain; confusion; headache; seizures; nausea; vomiting; diarrhoea; abdominal pain; poor appetite; skin ulcers or rash; ear pain; conjunctivitis; anosmia; bleeding; lymphadenopathy. the attending clinician will determine if symptoms are consistent with covid-19. clinical status not requiring admission to hospital for covid-19 disease and oxygen support ability to transfuse (per randomisation) within 7 days after onset of symptoms men or women, 70 years or older or under 70 years with significant comorbidities (arterial hypertension, diabetes, obesity, asthma or other chronic pulmonary disease, cardiovascular disease, cerebrovascular disease, chronic kidney disease / dialysis, hemoglobinopathies, liver disease, chronic neurological disease, rheumatoid arthritis, lupus or psoriasis) resulting in a 'covid-age' of 70 years or more according to the alama risk calculator https://alama.org.uk/covid-19-medical-risk-assessment/

cohort 1: elderly and high covid-age population: inclusion criteria: sars-cov-2 rna detected in a specimen, ≤ 7 days after onset of symptoms symptoms of covid-19 (so including but not limited to: fever; cough; breathlessness; chest pain; wheeze; sore throat; haemoptysis; runny nose; fatigue; muscle or joint pain; confusion; headache; seizures; nausea; vomiting; diarrhoea; abdominal pain; poor appetite; skin ulcers or rash; ear pain; conjunctivitis; anosmia; bleeding; lymphadenopathy. the attending clinician will determine if symptoms are consistent with covid-19. clinical status not requiring admission to hospital for covid-19 disease and oxygen support ability to transfuse (per randomisation) within 7 days after onset of symptoms men or women, 70 years or older or under 70 years with significant comorbidities (arterial hypertension, diabetes, obesity, asthma or other chronic pulmonary disease, cardiovascular disease, cerebrovascular disease, chronic kidney disease / dialysis, hemoglobinopathies, liver disease, chronic neurological disease, rheumatoid arthritis, lupus or psoriasis) resulting in a 'covid-age' of 70 years or more according to the alama risk calculator https://alama.org.uk/covid-19-medical-risk-assessment/

cohort 1: elderly and high covid-age population: inclusion criteria: sars-cov-2 rna detected in a specimen, ≤ 5 days after onset of symptoms symptoms of covid-19 (so including but not limited to: fever; cough; breathlessness; chest pain; wheeze; sore throat; haemoptysis; runny nose; fatigue; muscle or joint pain; confusion; headache; seizures; nausea; vomiting; diarrhoea; abdominal pain; poor appetite; skin ulcers or rash; ear pain; conjunctivitis; anosmia; bleeding; lymphadenopathy. the attending clinician will determine if symptoms are consistent with covid-19. clinical status not requiring admission to hospital for covid-19 disease and oxygen support ability to transfuse (per randomisation) within 5 days after onset of symptoms men or women, 70 years or older or under 70 years with significant comorbidities (arterial hypertension, diabetes, obesity, asthma or other chronic pulmonary disease, cardiovascular disease, cerebrovascular disease, chronic kidney disease / dialysis, hemoglobinopathies, liver disease, chronic neurological disease, rheumatoid arthritis, lupus or psoriasis) resulting in a 'covid-age' of 70 years or more according to the alama risk calculator https://alama.org.uk/covid-19-medical-risk-assessment/

cohort 1: elderly and high covid-age population: inclusion criteria: sars-cov-2 rna detected in a specimen, ≤ 5 days after onset of symptoms symptoms of covid-19 (so including but not limited to: fever; cough; breathlessness; chest pain; wheeze; sore throat; haemoptysis; runny nose; fatigue; muscle or joint pain; confusion; headache; seizures; nausea; vomiting; diarrhoea; abdominal pain; poor appetite; skin ulcers or rash; ear pain; conjunctivitis; anosmia; bleeding; lymphadenopathy. the attending clinician will determine if symptoms are consistent with covid-19. clinical status not requiring admission to hospital for covid-19 disease and oxygen support ability to transfuse (per randomisation) within 5 days after onset of symptoms men or women, 70 years or older or under 70 years with significant comorbidities (arterial hypertension, diabetes, obesity, asthma or other chronic pulmonary disease, cardiovascular disease, cerebrovascular disease, chronic kidney disease / dialysis, hemoglobinopathies, liver disease, chronic neurological disease, rheumatoid arthritis, lupus or psoriasis) resulting in a 'covid-age' of 70 years or more according to the alama risk calculator https://alama.org.uk/covid-19-medical-risk-assessment/