Thanks to one of the newest quests, The Branches of Darkmeyer, players have gained extremely helpful weapons against the vampires. As I have tested with at least the polearm, all blisterwood weapons(thanks to the description from the quest, something like the wood is alive and erratically moves) can damage vampires and vyrewatches. Compared to the flail of ivandis, these weapons slaughter them. Just a pointer to add it into the temple trekking/burgh de rott ramble activity. Will post pictures if requested.