Immunity to specific disadvantage

[Flyndaran]

Originally Posted by munin

Immunity to Specific Poison is an Exotic perk -- regular humans can only take the Resistant to Specific Poison (+3) perk.

Immunity to a specific disadvantage from one specific source (a drug, a spell, etc.) might be worth only a perk, but if it's immunity to all possible sources, then it's worth more. I'd call it Rare for [5].

If things like poison ivy/oak count as a poison, then real people can have immunity to it like my family.