inclusion criteria: 1. aged 18 to 65 years old (including 18 and 65 years); 2. male and non-pregnant female; 3. respiratory tract specimens or hematology samples detected positive results of sars-cov-2 by real-time transcriptase polymerase chain reaction (rt-pcr). 4. mild clinical status, defined as having mild clinical symptoms but no signs of pneumonia on imaging or moderate clinical status, defined as having fever, respiratory symptoms and pneumonia on imaging or severe clinical status, defined as having an oxygen saturation (sao2) of 93% or less at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) at or below 400 mghg, which can be rectified by oxygen inhalation through nasal catheter or face mask.

inclusion criteria: 1. aged 18 to 65 years old (including 18 and 65 years); 2. male and non-pregnant female; 3. respiratory tract specimens or hematology samples detected positive results of sars-cov-2 by real-time transcriptase polymerase chain reaction (rt-pcr). 4. mild clinical status, defined as having mild clinical symptoms but no signs of pneumonia on imaging or moderate clinical status, defined as having fever, respiratory symptoms and pneumonia on imaging or severe clinical status, defined as having an oxygen saturation (sao2) of 93% or less at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) at or below 400 mghg, which can be rectified by oxygen inhalation through nasal catheter or face mask.

inclusion criteria: aged 18 to 65 years old (including 18 and 65 years); male and non-pregnant female; respiratory tract specimens or hematology samples detected positive results of sars-cov-2 by real-time transcriptase polymerase chain reaction (rt-pcr). mild clinical status, defined as having mild clinical symptoms but no signs of pneumonia on imaging or moderate clinical status, defined as having fever, respiratory symptoms and pneumonia on imaging or severe clinical status, defined as having an oxygen saturation (sao2) of 93% or less at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) at or below 400 mghg, which can be rectified by oxygen inhalation through nasal catheter or face mask.

inclusion criteria: aged 18 to 65 years old (including 18 and 65 years); male and non-pregnant female; respiratory tract specimens or hematology samples detected positive results of sars-cov-2 by real-time transcriptase polymerase chain reaction (rt-pcr). mild clinical status, defined as having mild clinical symptoms but no signs of pneumonia on imaging or moderate clinical status, defined as having fever, respiratory symptoms and pneumonia on imaging or severe clinical status, defined as having an oxygen saturation (sao2) of 93% or less at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) at or below 400 mghg, which can be rectified by oxygen inhalation through nasal catheter or face mask.

inclusion criteria: 1. aged 18 to 65 years old (including 18 and 65 years); 2. male and non-pregnant female; 3. respiratory tract specimens or hematology samples detected positive results of sars-cov-2 by real-time transcriptase polymerase chain reaction (rt-pcr). 4. mild clinical status, defined as having mild clinical symptoms but no signs of pneumonia on imaging or moderate clinical status, defined as having fever, respiratory symptoms and pneumonia on imaging or severe clinical status, defined as having an oxygen saturation (sao2) of 93% or less at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) at or below 400 mghg, which can be rectified by oxygen inhalation through nasal catheter or face mask.

inclusion criteria: 1. aged 18 to 65 years old (including 18 and 65 years); 2. male and non-pregnant female; 3. respiratory tract specimens or hematology samples detected positive results of sars-cov-2 by real-time transcriptase polymerase chain reaction (rt-pcr). 4. mild clinical status, defined as having mild clinical symptoms but no signs of pneumonia on imaging or moderate clinical status, defined as having fever, respiratory symptoms and pneumonia on imaging or severe clinical status, defined as having an oxygen saturation (sao2) of 93% or less at ambient air or a ratio of the partial pressure of oxygen (pao2) to the fraction of inspired oxygen (fio2) at or below 400 mghg, which can be rectified by oxygen inhalation through nasal catheter or face mask.

inclusion criteria: 1. sign the informed consent form; 2. age ≥18 years, regardless of gender; 3. subjects with pneumonia diagnosed as 2019-ncov infection; a) detection of 2019-ncov nucleic acid positive by rt-pcr in respiratory tract or blood samples. b) the virus gene sequence of respiratory tract or blood samples is highly homologous to the known 2019-ncov. 4. according to the standard of "pneumonia diagnosis and treatment program of new coronavirus infection (trial fifth edition)" issued by national health commission of the people's republic of china, clinical classification: mild, ordinary subjects; a) mild type, the clinical symptoms were mild and no pneumonia was found in imaging. b) common type, with fever, respiratory tract and other symptoms, the manifestations of pneumonia can be seen on imaging.

inclusion criteria: 1. sign the informed consent form; 2. age ≥18 years, regardless of gender; 3. subjects with pneumonia diagnosed as 2019-ncov infection; a) detection of 2019-ncov nucleic acid positive by rt-pcr in respiratory tract or blood samples. b) the virus gene sequence of respiratory tract or blood samples is highly homologous to the known 2019-ncov. 4. according to the standard of "pneumonia diagnosis and treatment program of new coronavirus infection (trial fifth edition)" issued by national health commission of the people's republic of china, clinical classification: mild, ordinary subjects; a) mild type, the clinical symptoms were mild and no pneumonia was found in imaging. b) common type, with fever, respiratory tract and other symptoms, the manifestations of pneumonia can be seen on imaging.