plague_recovery_event_effect

plague_recovery_event_effect = {
	county.holder.liege = {
		add_to_variable_list = {
			name = formerly_infected_counties
			target = root.county
			years = 10
		}
	}
	scope:epidemic = {
		add_to_variable_list = {
			name = lieges_to_notify
			target = root.county.holder.liege
		}		
		every_in_list = {
			variable = lieges_to_notify
			limit = {
				is_alive = yes # dead people do seem to sneak into the list, so we need to check
				NOT = {
					has_character_flag = notified_of_plague_recovery
				}
			}
			trigger_event = {
				id = epidemic_events.0110
				days = 1
			}
			add_character_flag = {
				flag = notified_of_plague_recovery
				days = 10
			}
		}
	}
}

As written in game/common/scripted_effects/06_dlc_ce1_epidemics_effects.txt.