Not really on both parts. It's only transferred by eating meat so the defence is as soon as prion infection is detected all possibly infested livestock is culled and severe bans on trading are placed. Cannibalism in animal feed is also disallowed which makes transmission rare. Being vegetarian is also a complete defence.

They're also rare to appear, otherwise eating livestock would have regularly wiped out humans already. They're basically non-existent if you don't eat humans and livestock isn't fed to livestock.