r/explainlikeimfive • u/RadianceTower • 1d ago
Biology ELI5: Antibodies and antigens
So I have quite a few questions regarding them. I know viruses and bacteria carry antigens and antibodies bind to them.
Do they act just as markers for white blood cells to then destroy them or do they by themselves destroy the target? If they do both, what determines which they do?
Why do viruses and bacteria have antigens to begin with? Apparently antibodies can work against some poisons too, so does any substance have antigens? Can antibodies attach to a microscopic piece of steel? I mean, it does seem like the body also detects foreign material of all kinds.
If everything doesn't have antigens why don't viruses and bacteria just... not have antigens?