Prions are not microorganisms. They are proteins, which can misfold and thereby lead to prion-diseases.

Therein lies the problem of curing these diseases. There is no easy way of destroying proteins in the body, much less so if they are not inherently foreign to the immune system.

This might be of interest: https://www.thelancet.com/article/S1474-4422(22)00082-5/fulltext