Well, you don't really *need* to protect the part that's already covered by the sternum. I suppose it wouldn't hurt to have a redundancy, but since vampires don't have to worry about lung puncturing it probably isn't that big of a deal.

Unless someone figures out a way to make high-caliber wooden bullets. In which case, she's screwed.

Certain varieties of Mark VII .303 British ammunition used a wooden tip under the full metal jacket to lighten the round and give it better ballistic properities, as well as cause it to deform and tumble on impact. Would probably work well for dusting Vrykos....