I have fired non-consumer Tasers a number of times (at targets, not a living things). The thin needles of a Taser are more likely to pentrate armor than a lage knife. And a knife is more likely than a bullet. Bulletproof vests are not necessarily knife proof, they capture bullets by binding them and dissipating energy rather than stopping them dead (that is what ballistic plates/inserts are for)

That said needle proof vets are common and used by law enforcement.

I was trying to work out why on earth you would need to wear a metal conductor whilst erecting a fence and then I realized that you mean the sport of fencing. Ha, ha.