(1) Hospitalized patients under treatment who were severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] positive by polymerase chain reaction (PCR) test.(2) Patients with clinically diagnosed pneumonia and a percutaneous oxygen saturation [SpO2] of 93% or less on breathing of room air at bed rest.(3) Patients for whom written informed consent has been obtained from those themselves or the legally acceptable representatives.(4) Patients aged 20 years or older and younger than 85 years at the time of obtaining informed consent.

(1) Hospitalized patients under treatment who were severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] positive by polymerase chain reaction (PCR) test.(2) Patients with clinically diagnosed pneumonia and a percutaneous oxygen saturation [SpO2] of 93% or less on breathing of room air at bed rest.(3) Patients for whom written informed consent has been obtained from those themselves or the legally acceptable representatives.(4) Patients aged 20 years or older and younger than 85 years at the time of obtaining informed consent.

(1) Hospitalized patients under treatment who were severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] positive by polymerase chain reaction (PCR) test.(2) Patients with clinically diagnosed pneumonia and a percutaneous oxygen saturation [SpO2] of 93% or less on breathing of room air at bed rest.(3) Patients for whom written informed consent has been obtained from those themselves or the legally acceptable representatives.(4) Patients aged 20 years or older and younger than 80 years at the time of obtaining informed consent.

(1) Hospitalized patients under treatment who were severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] positive by polymerase chain reaction (PCR) test.(2) Patients with clinically diagnosed pneumonia and a percutaneous oxygen saturation [SpO2] of 93% or less on breathing of room air at bed rest.(3) Patients for whom written informed consent has been obtained from those themselves or the legally acceptable representatives.(4) Patients aged 20 years or older and younger than 80 years at the time of obtaining informed consent.