I’ve had both. This (long covid, post virus fatigue, whatever) is a few orders of magnitude worse, at least for me.

I had covid middle of March, and am maybe 50% energy most days, and have to do massive breaths every so often. After 7 months of “recovery”?! I don’t know if I’m even getting better... yeah extreme fatigue, brain fog, eating can be exhausting...

OTOH, A lot of people came out of it far worse...

Looking up "mono brain fog", there seem to be a lot of reports of people experiencing neurological symptoms for many months, even years. Symptoms reported are similar - fatigue, brain fog, decreased appetite, some also seem to report anxiety and other similar changes.

But it seems to be rare enough that it is hard to establish a causal link / study it properly.

I wonder if there could be some common cause? Perhaps also common to CFS?

Thanks for this comparison.

I'm not sure how common symptomatic mono is, but I suspect it (along with some things like maybe pneumonia and bronchitis?) is a good reference point.

How was your bout with mono? I recall having tonsils so swollen I was afraid I'd have to go to the hospital for a few days, and then being perpetually exhausted for ~6-8 weeks.

Yeah for me mono was horrible for a week or so, then exhaustion for 2-3 months but nothing like long covid. Of course it could also be partly the fact I had mono in my early 20s and had covid in early 40s!