Comment by bsder

That's really interesting. I wonder if the immune system is modal - I know there are tons of systems in place that kick it into gear for response to an infection, so I guess its reasonable to assume that the body prefers to keep it as dormant as possible the rest of the time to minimise auotimmune disease risks and the like.

If these sorts of disorders creep in underneath it, and persist at a sufficiently low level not to trigger it, I suppose these things can hang around. I wonder why the immune system can't clear it out otherwise though (since presumable plenty of other immune systems have to always be active, to prevent infections from cuts and the like from being imminently fatal..)

Perhaps this suggest that a treatment for long covid might be a new exposure to covid itself - or maybe a safer drug that mimics covid, like a vaccine or something analogous, that gives the benefit of "restarting" the immune response, but without the complications of real covid.

I think a lot of the problem here is the stunning complexity of the immune systems in living systems. A huge part of our immune system isn't our own, it's other viruses and bacteria that live in symbiosis with us. The war of the viruses and bacteria was going on for billions of years before cells decided to clump together and make anything complicated.