> If you don't have worms, ivermectin will not help you
This makes sense and is supported by some data.
> COVID outcomes are better without parasites
This dramatically understates interactions in the immune system. I can go into a longer essay, but:
1) Parasites suppress the immune system (they release chemicals to moderate immune response; otherwise, the immune system would destroy them)
2) There is some evidence that the immune system evolved to operate when suppressed by worms. Autoimmune diseases and allergies may be a symptom of worm-free life.
3) Most of the damage from COVID19 comes from the immune system and not the disease (that's true of most diseases, for that matter).
4) ... and so on.
We have absolutely no idea how ivermectin, worms, and COVID interact. It's too complex a system.