1. patient with severe condition meeting one of the following: 1. respiratory distress with respiratory rate ≥ 30 breaths/min. 2. requires supplemental oxygen. 3. experience shock. 4. complicated with other organs failure, and intensive care unit monitoring treatment is needed by investigator's discretion. 5. any other conditions suspected of being severe symptoms of sars-cov-2 infection, in the opinion of the investigator, including but not limited to radiographic findings in lung.

1. patient with severe condition meeting one of the following: 1. respiratory distress with respiratory rate ≥ 30 breaths/min. 2. requires supplemental oxygen. 3. experience shock. 4. complicated with other organs failure, and intensive care unit monitoring treatment is needed by investigator's discretion. 5. any other conditions suspected of being severe symptoms of sars-cov-2 infection, in the opinion of the investigator, including but not limited to radiographic findings in lung.

1. patient with severe condition meeting one of the following: respiratory distress with respiratory rate ≥ 30 breaths/min. requires supplemental oxygen. experience shock. complicated with other organs failure, and intensive care unit monitoring treatment is needed by investigator's discretion. any other conditions suspected of being severe symptoms of sars-cov-2 infection, in the opinion of the investigator, including but not limited to radiographic findings in lung.

1. patient with severe condition meeting one of the following: respiratory distress with respiratory rate ≥ 30 breaths/min. requires supplemental oxygen. experience shock. complicated with other organs failure, and intensive care unit monitoring treatment is needed by investigator's discretion. any other conditions suspected of being severe symptoms of sars-cov-2 infection, in the opinion of the investigator, including but not limited to radiographic findings in lung.

1. patient with severe condition meeting one of the following: 1. respiratory distress with respiratory rate ≥ 30 breaths/min. 2. requires supplemental oxygen. 3. experience shock. 4. complicated with other organs failure, and intensive care unit monitoring treatment is needed by investigator's discretion. 5. any other conditions suspected of being severe symptoms of sars-cov-2 infection, in the opinion of the investigator, including but not limited to radiographic findings in lung.

1. patient with severe condition meeting one of the following: 1. respiratory distress with respiratory rate ≥ 30 breaths/min. 2. requires supplemental oxygen. 3. experience shock. 4. complicated with other organs failure, and intensive care unit monitoring treatment is needed by investigator's discretion. 5. any other conditions suspected of being severe symptoms of sars-cov-2 infection, in the opinion of the investigator, including but not limited to radiographic findings in lung.