Melissa Red Hoffman was “feeling really stuck” last summer. A 50-year-old surgeon in Asheville, N.C., Hoffman had been struggling with long COVID since getting infected with the coronavirus two and a half years earlier. “Deafening fatigue” was one of her worst symptoms, she says. “I feel tired behind my eyes from the moment I get up to the moment I go to sleep.” She managed to work part time, but much of her work had shifted to administrative tasks that she did from her couch. “I was real...