[Scandiravian]

I think the timescale is too long for it to be an effective tool for terrorists

Terrorism is first and foremost a propaganda strategy to destabilise the political system in the target country and recruit new members to the organisations cause

Since prions take decades to progress, a terrorist attack using such a weapon, would probably not create the shock and outrage, that makes headlines

[oxymoran]

It would be the perfect timetable for an adversarial country looking to become the next superpower to use as a bio weapon though.