A person is contagious with COVID-19 for about 5 days, but this can be different as it depends on the immune system health, Vaccination status and the Severity of symptoms as patients with mild or no symptoms may be less contagious for a shorter period ( it takes from 2-3 days before symptoms begin). Those with severe Cases or Immunocompromised Individuals, the contagious period can last up to 20 days or more.