noun
Medical and biological sense: the body's ability to resist infection, or the process of becoming immune.
ワクチンで免疫をつける。
Build immunity with a vaccine.
一度かかると免疫ができる病気もある。
Some diseases give you immunity once you've had them.
noun
being hardened; being unaffected; being accustomed
Figurative extension: so used to criticism, hardship, or a situation that one is no longer bothered by it. Often used with 〜に免疫がある or 〜に免疫ができる.
彼は批判に免疫がある。
He is immune to criticism.
都会の騒音にはもう免疫ができた。
I've become accustomed to the noise of the city.