Survey of people with mostly mild COVID: “persistent symptoms were reported by 17 of 64 patients (26.6%) aged 18 to 39 years, 25 of 83 patients (30.1%) aged 40 to 64 years, and 13 of 30 patients (43.3%) aged 65 years and older.”

Link. Persistent symptoms mostly loss of smell/taste, fatigue, “brain fog”.