A simple blood test for long COVID is on the horizon. Biological “fingerprints” can identify individuals with the debilitating syndrome, according to new research. This opens the door to the first accurate diagnosis of the mysterious condition. Sufferers complain it is hard to convince doctors of their disease. Long COVID is an umbrella term for symptoms of the virus lasting more than 12 weeks. They range from fatigue, headaches, and breathlessness to fever and tummy pain. At least one fourth of patients have developed some form of long COVID, per research out of the University of California, Davis. “We need...