inclusion criteria: - patients are eligible to be included in the study only if they fulfil all the following criteria: - rt-pcr confirmed covid-19 cases - aged 50 years and above, and have one or more co-morbidities - within the first 7 days of illness (from symptom onset) - mild to moderate clinical severity

inclusion criteria: - patients are eligible to be included in the study only if they fulfil all the following criteria: - rt-pcr confirmed covid-19 cases - aged 50 years and above, and have one or more co-morbidities - within the first 7 days of illness (from symptom onset) - mild to moderate clinical severity