In an article earlier today, the covid virus was made by at lease, splicing a a piece of HIV genetic material into an RNA string
So, Those HIV positive but not having full blown AIDS might have covid immunity. We don’t know what else she put in there but there might be other diseases that produce immunity as well
I think I heard something about that much earlier, and it wasn’t a reviewed study.
I’m leaning more toward the accidental escape of something already in a human population somewhere, and which was being studied - but again, I’m not a scientist.