The plague has a bug.
Provinces with hospitals and using NB and still unable to remove the plague after 14 hours. Yet a spell like chastity which has the same peasant growth effects only lasts a few ticks. It is a massive bug in the game that plague lasts far too long and one as an attacker needs to play either Undead or the cleric personality, if other things in the game don't work. It is a killer of hybrids.
It should last the same length as chastity which in itself is a far weaker thing than plague.
It is a joke, players affected and who can't fix it are fed up of the overpowered length and effects.
Great for Undead and clerics, but it is like a developers bug in the game at this stage.