Why do you believe this out of curiosity? Every single "long term covid" symptom study I've read are case studies. The UK one from the publication in Charlottesville covered 60 distinct people and they were all either high risk workers or over 55.
We don't know what "permanent damage" is actually happening. I remember having pneumonia in the 90s and it took my lungs over 3 months to recover, and that's from a normal known infection.
I think there is a strong case to be made, that a lot of these "long covid" cases might be a combination of normal pneumonia recovery, nocebo effect and fear/hysteria over this disease.
We don't know what "permanent damage" is actually happening. I remember having pneumonia in the 90s and it took my lungs over 3 months to recover, and that's from a normal known infection.
I think there is a strong case to be made, that a lot of these "long covid" cases might be a combination of normal pneumonia recovery, nocebo effect and fear/hysteria over this disease.