If you're interested in Biomarkers for Long Covid and ME/CFS, look up Chronic Inflammatory Response Syndrome (CIRS). MMP-9, MSH, ACTH, TGF-beta 1, Cortisol, Glutathione, and Vasoactive Intestinal Peptide are a few of them. Lots of research here that was started by illnesses triggered by mold mycotoxins and lyme disease - the initial trigger is different than Covid - but the end result in terms of biomarkers and dysregulation in the body is the same. Doctors have been using these protocols to successfully treat patients for a few years now, but it just hasn't trickled down to the mainstream medical community or the medical schools yet.