What is the reason for COVID-19 severe and mild?

Media coverage

• Title	What is the reason for COVID-19 severe and mild?
  Media name/outlet	Archyde
  Country/Territory	United States
  Date	21/12/21
  URL	https://www.archyde.com/what-is-the-reason-for-covid-19-severe-and-mild/
  Persons	Dong Sup Lee, Dong Gun Lee