1. Subject is considered to be in their last few weeks of life prior to this acute illness 2. Clinical frailty score of 8 or 9 prior to this acute illness 3. History of haematopoietic stem cell transplant or solid organ transplant 4. Chronic obstructive pulmonary disease (COPD) on long term oxygen therapy (Subjects with FEV1 known to be <50% will also be excluded) 5. Concomitant use of DMARDs (including csDMARDs, tsDMARDs and bDMARDs) or other immuno-suppressants 6. Previous malignancy and lymphoproliferative disorders (within the last 5 years) with the exception of stable prostate cancer and basal cell carcinoma 7. Current participation in another therapeutic interventional clinical study for COVID-19 8. De-myelinating disease 9. Known to be co-infected with Hepatitis B Virus, HIV 10. Severe hepatic impairment 11. Acute Kidney Injury Stage 3 (NHS England Acute Kidney Injury algorithm) 12. Patients with tuberculosis or other severe infections such as (non-COVID-19) sepsis, abscesses, fungal superinfection and opportunistic infections requiring treatment. 13. Moderate or severe heart failure (NYHA class III/IV) 14. Treatment with anti-TNF drug in past 180 days (9 half lives of the drug) 15. Pregnancy 16. Lactating females 17. Women of childbearing potential who are unwilling to use effective contraception (i.e. barrier, oral contraceptive pill, implanted contraception, or previous hysterectomy, bilateral oophorectomy) for the study and 5 months afterwards

1. Subject is considered to be in their last few weeks of life prior to this acute illness 2. Clinical frailty score of 8 or 9 prior to this acute illness 3. History of haematopoietic stem cell transplant or solid organ transplant 4. Chronic obstructive pulmonary disease (COPD) on long term oxygen therapy (Subjects with FEV1 known to be <50% will also be excluded) 5. Concomitant use of DMARDs (including csDMARDs, tsDMARDs and bDMARDs) or other immuno-suppressants 6. Previous malignancy and lymphoproliferative disorders (within the last 5 years) with the exception of stable prostate cancer and basal cell carcinoma 7. Current participation in another therapeutic interventional clinical study for COVID-19 8. De-myelinating disease 9. Known to be co-infected with Hepatitis B Virus, HIV 10. Severe hepatic impairment 11. Acute Kidney Injury Stage 3 (NHS England Acute Kidney Injury algorithm) 12. Patients with tuberculosis or other severe infections such as (non-COVID-19) sepsis, abscesses, fungal superinfection and opportunistic infections requiring treatment. 13. Moderate or severe heart failure (NYHA class III/IV) 14. Treatment with anti-TNF drug in past 180 days (9 half lives of the drug) 15. Pregnancy 16. Lactating females 17. Women of childbearing potential who are unwilling to use effective contraception (i.e. barrier, oral contraceptive pill, implanted contraception, or previous hysterectomy, bilateral oophorectomy) for the study and 5 months afterwards

1. Subject is considered to be in their last few weeks of life prior to this acute illness 2. Clinical frailty score of 8 or 9 prior to this acute illness 3. History of haematopoietic stem cell transplant or solid organ transplant 4. Chronic Obstructive Pulmonary Disease on long term oxygen therapy (Subjects with FEV1 known to be <50% will also be excluded) 5. Concomitant use of DMARDs (including csDMARDs, tsDMARDs and bDMARDs) or other immuno-suppressants 6. Previous malignancy and lymphoproliferative disorders (within the last 5 years) with the exception of stable prostate cancer and basal cell carcinoma 7. Current participation in another therapeutic interventional clinical study for COVID-19 8. De-myelinating disease 9. Known to be co-infected with Hepatitis B Virus, HIV 10. Severe hepatic impairment 11. Acute Kidney Injury Stage 3 (NHS England Acute Kidney Injury algorithm) 12. Patients with tuberculosis or other severe infections such as (non-COVID-19) sepsis, abscesses, fungal superinfection and opportunistic infections requiring treatment. 13. Moderate or severe heart failure (NYHA class III/IV) 14. Treatment with anti-TNF drug in past 180 days (9 half lives of the drug) 15. Pregnancy 16. Lactating females 17. Women of childbearing potential who are unwilling to use effective contraception (i.e. barrier, oral contraceptive pill, implanted contraception, or previous hysterectomy, bilateral oophorectomy) for the study and 5 months afterwards

1. Subject is considered to be in their last few weeks of life prior to this acute illness 2. Clinical frailty score of 8 or 9 prior to this acute illness 3. History of haematopoietic stem cell transplant or solid organ transplant 4. Chronic Obstructive Pulmonary Disease on long term oxygen therapy (Subjects with FEV1 known to be <50% will also be excluded) 5. Concomitant use of DMARDs (including csDMARDs, tsDMARDs and bDMARDs) or other immuno-suppressants 6. Previous malignancy and lymphoproliferative disorders (within the last 5 years) with the exception of stable prostate cancer and basal cell carcinoma 7. Current participation in another therapeutic interventional clinical study for COVID-19 8. De-myelinating disease 9. Known to be co-infected with Hepatitis B Virus, HIV 10. Severe hepatic impairment 11. Acute Kidney Injury Stage 3 (NHS England Acute Kidney Injury algorithm) 12. Patients with tuberculosis or other severe infections such as (non-COVID-19) sepsis, abscesses, fungal superinfection and opportunistic infections requiring treatment. 13. Moderate or severe heart failure (NYHA class III/IV) 14. Treatment with anti-TNF drug in past 180 days (9 half lives of the drug) 15. Pregnancy 16. Lactating females 17. Women of childbearing potential who are unwilling to use effective contraception (i.e. barrier, oral contraceptive pill, implanted contraception, or previous hysterectomy, bilateral oophorectomy) for the study and 5 months afterwards