Inclusion Criteria:  Aged above 18; Have fatigue and one more residue symptoms (e.g. dyspnoea, sleep disturbance, cough, loose stool, abdominal distension, loss of appetite, dizziness, etc.) at least 5 weeks after discharge Patients are diagnosed with "lung-spleen qi deficiency"(肺脾氣虛) and/or"dual deficiency of qi and yin"(氣陰兩虛) by a Chinese Medicine Practitioner Voluntary written consent.  Exclusion Criteria:  Still being SARS-CoV-2 positive Known severe medical conditions, such as cardiovascular, liver or renal dysfunction, diabetes mellitus, cancers, cerebrovascular diseases, blood system diseases; Impaired hematological profile and liver / renal function; No concomitant non-steroidal anti-inflammatory drugs (NSAIDs), steroids, antibiotics, prebiotics, probiotics within 4 weeks; Known allergic history to any Chinese herbal medicines; Known pregnancy or lactating.