I don't think vampires are turning anyone. I think people re either seeing vampire townies or sims in vampire clothing (similar to the day of the dead challenge).
But yeah, many people on tumblr have confirmed that deleting Vlad before he even sneaks into a house is the key. So the moment you start your save, go to household managements, delete the vampires, and then play a household and no vampire break ins should happen. Then avoid anything vampire related and don't use the new lot traits and the amount of vampires spawned should be extremely low. They'll appear but very rarely. If they appear as a waiter, I guess you can pretend that your sim needs to lay off the nectar. Hopefully once MCC updates, there will be option to humanize vamps. Until then just put garlic in your sims inventory and in the garden
