Inclusion Criteria:

1. Age ≥18 years old;

2. A record of positive SARS-CoV-2 nucleic acid test results on the day of admission or
on the second day;

3. Diagnosed as mild or common novel coronavirus pneumonia on admission, or with at
least one of the following COVID-19-related symptoms on admission: fever, cough,
sore throat, nasal congestion or runny nose, headache, muscle pain, nausea,
vomiting, diarrhea , shortness of breath or difficulty breathing, chills or chills;

4. Documented or diagnosed high risk factors for progression to severe COVID-19
(including death) with one or more of the following:

- Age ≥ 60 years

- Cardiovascular disease (including congenital heart disease) or high blood
pressure

- Chronic lung disease (eg chronic obstructive pulmonary disease [COPD], asthma
[moderate to severe], interstitial lung disease, cystic fibrosis and pulmonary
hypertension)

- diabetes

- Has an immunosuppressive disorder or is receiving immunosuppressive therapy
(eg, long-term use of corticosteroids or other immunosuppressive drugs leading
to decreased immune function)

- Obese or overweight (BMI>25 kg/m2)

- Sickle cell disease

- Active cancer

- Chronic kidney disease

- Current smokers

- Neurodevelopmental disorders (eg, cerebral palsy, Down syndrome) or other
conditions that cause medical complexity (eg, genetic or metabolic syndrome and
severe congenital anomalies)

- Need for relevant medical support (not related to COVID-19) (eg tracheostomy,
gastrostomy or positive pressure ventilation, etc.)

Exclusion Criteria:

1. Diagnosed with severe/critical COVID-19 before or on the day of admission;

2. There is a data record of having received the following treatments before
progression to severe/critical COVID-19:

- Nematicavir/ritonavir combination package (ie Paxlovid)

- SARS-CoV-2 monoclonal antibody (Ambavirumab/Romisevirumab)

- Convalescent COVID-19 plasma

- Other anti-SARS-CoV-2 drugs under investigation