I've always found that when it's completely fucked, the best thing to do is get some credible witnesses to imply some kind of psychedelic introduced into the air/water/whatever system, note that all the witnesses tell different stories (ENFORCING the differences, if necessary), produce a blood-soaked lunatic who had a psychotic break and really did start killing people and drinking their blood when exposed to this psychedelic chemical, and just make sure that anyone who REALLY DOES stick to the "No, real vampires! Tearing limbs off with bare hands! Moving faster than THOUGHT!" line of things gets committed to a nice, quiet asylum somewhere.

And yeah, I probably would have killed you all, too. Sparky, man, those botches and frenzies? That's why they invented Willpower.

(Gerat story)