Vampires in SPN

[hils]

Am I right in thinking that the only way to kill a vampire in the SPN universe is to cut its head off? I know you can incapacitate them with dead man's blood but that doesn't kill them, right?

Isn't it really hard to cut someone's head off? Yet I recall Sam decapitating Harmony (or whatever Mercedes McNab's character was called) with one blow of a machete.

Interesting...