unaffected vs immune

unaffected is not a noun while immune is a noun.

Word	Noun	Adjective	Verb	Adverb
unaffected	No	Yes	No	No
immune	Yes	Yes	No	No

unaffected (noun)	immune (noun)
	a person who is immune to a particular infection

unaffected (adjective)	immune (adjective)
undergoing no change when acted upon	relating to the condition of immunity
free of artificiality; sincere and genuine	secure against
emotionally unmoved	(usually followed by `to') not affected by a given influence
unaware of or indifferent to	relating to or conferring immunity (to disease or infection)