“Adults with severe illness who spend weeks in intensive care, often intubated, can experience long-lasting symptoms, but that’s not unique to patients with COVID-19. What’s unusual about the long haulers is that many initially had mild to moderate symptoms that didn’t require lengthy hospitalization—if any—let alone intensive care.  “Most of the patients that I see who are suffering from [post–COVID-19] syndrome were not hospitalized,” Jessica Dine, MD, a pulmonary specialist at the University of Pennsylvania Perelman School of Medicine, said in an interview. “They were pretty sick, but still at home.””