World Health Organization (WHO), the total number of COVID-19 cases has surpassed 190 million globally, with the death toll crossing 4 million.
As the COVID-19 pandemic has progressed, it has become evident that besides the potential of developing severe or fatal illness during the first few weeks, a SARS-CoV-2 infection may also result in prolonged illness in some people.Most individuals with COVID-19 develop mild-to-moderate symptoms and recover within 2–3 weeks after symptom onset.
However, a small but significant number of individuals tend to experience persistent symptoms beyond 4 weeks after developing COVID-19.