inclusion criteria: * hospitalized patients with severe covid-19 (5 point on nih 8-point ordinal scale). * male or female adult ≥18 years of age at time of enrollment; * biological samples (not limited to any specific type) collected within 72 hours before randomization is laboratory-confirmed as sars-cov-2 infection (pcr or antigen-based diagnostic tests); * ≤ 10 days since symptoms of covid-19 onset.

inclusion criteria: * hospitalized patients with severe covid-19 (5 point on nih 8-point ordinal scale). * male or female adult ≥18 years of age at time of enrollment; * biological samples (not limited to any specific type) collected within 72 hours before randomization is laboratory-confirmed as sars-cov-2 infection (pcr or antigen-based diagnostic tests); * ≤ 10 days since symptoms of covid-19 onset.

inclusion criteria: - hospitalized patients with severe covid-19 (5 point on nih 8-point ordinal scale). - male or female adult ≥18 years of age at time of enrollment; - biological samples (not limited to any specific type) collected within 72 hours before randomization is laboratory-confirmed as sars-cov-2 infection (pcr or antigen-based diagnostic tests); - ≤ 10 days since symptoms of covid-19 onset.

inclusion criteria: - hospitalized patients with severe covid-19 (5 point on nih 8-point ordinal scale). - male or female adult ≥18 years of age at time of enrollment; - biological samples (not limited to any specific type) collected within 72 hours before randomization is laboratory-confirmed as sars-cov-2 infection (pcr or antigen-based diagnostic tests); - ≤ 10 days since symptoms of covid-19 onset.

inclusion criteria: - hospitalized patients with severe covid-19 (5 or 6 point on the 8-point ordinal scale). - male or female adult ≥18 years of age at time of enrollment; - biological samples (not limited to any specific type) collected within 72 hours before randomization is laboratory-confirmed as sars-cov-2 infection (pcr, etc.); - ≤ 10 days since symptoms of covid-19 onset.

inclusion criteria: - hospitalized patients with severe covid-19 (5 or 6 point on the 8-point ordinal scale). - male or female adult ≥18 years of age at time of enrollment; - biological samples (not limited to any specific type) collected within 72 hours before randomization is laboratory-confirmed as sars-cov-2 infection (pcr, etc.); - ≤ 10 days since symptoms of covid-19 onset.