Ok this is a spoiler for Vault 81 when you get there you will thank me later.[spoiler]Try your best to not get hit by the mole rats from the secret vault. You will get a permanent debuff and there is only one cure that you either have to use on yourself or the kid.[/spoiler][spoiler]Edit: this also goes for your companion if your companion gets hit you will still get sick. Fallout logic.[/spoiler]