Everything is a thing. Immune systems are, when all is said and done, physics. Simpler forms of death tend to be harder to evolve resistance against, but given enough generations it will happen. For example, microorganisms regularly evolve increasing resistance to sterilizing chemicals, such as enterococcus faecium evolving resistance to isopropanol, various species of bacillus increasing their resistance to hydrogen peroxide, pseudomonas evolving resistance to benzalkonium chloride, etc.