"We have a pretty strong inclination to believe the source of circulating spike in plasma of long covid patients may be from the bone marrow megakaryocytes that get infected during acute COVID. If so, constant exposure to spike on surface of circulating plasma EVs can account for persistent immune stimulation, immune exhaustion, and pro-thrombotic events stemming from spike stimulation. Please bear in mind that megakaryocytes from the bone marrow serve as the largest source of circulating plasma EVs (extracellular vesicles). What if these megakaryocytes are the source of spike in long covid?"