Still have to decide how vampires are affected by fire/water and if they can use fire based attacks.
Same goes for vulnerability to silver and garlic.

Forum post: http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/2756555-vampirism-become-a-vampire-release-for-mc-1-10-and?comment=7

Part of issue #122 related to this, created by @EpicCreeperHD:

The Vampire Hunters seem to be prepared for the wrong job. It is said that the smell of garlic is strong enough to overwhelm that of a rotting corpse and thus is too strong for a Vampire to stand with their heightened sense of smell, and yet it is being used to kill them, which it does not. This isn't surprising as the media had often led us to believe so, but we think that a smart idea would be to change the properties of the garlic to make it more of a repellant that disorientates and deters Vampires rather than doing them harm, and instead would opt for silver to take that role. In the old stories of Vampire Hunting, silver, fire and the wooden steak were the most common weapons. Silver was said to burn the skin and sometimes paralyze lesser Vampires like they were being electrocuted. Fire was said to destroy the Vampire in mere seconds. The stories say that they suffer much worse burns than any mortal man and that their flesh turns to ash once it is dead.

We feel like these could be reflected in-game. With silver weapons being made availiable to Vampire Hunters as well as some alchemical fire-based weaponry. If you decide to go through with these changes, we suggest that silver should hit Vampires much harder than the old iron stuff and have a small chance to stun them and disable their abilities. Real silver is heavier and softer than iron or steel, and should swing slower and have a lower durability to balance them. Fire should deal up to 4x normal damage that scales up and down with level (to make it really scary). If you need any ideas about fire weaponry, look at the class videos of Nosgoth for the Alchemist. With that in mind, perhaps watch them all. That game had some very nice anti-vampire gear that could act as some good suggestions.
I'll provide a link to the Alchemist's video:
https://www.youtube.com/watch?v=L2Vty5V-810

Ok decision have been made, I'm going with something like this:

Vampires won't get any fire based aggressive attacks (but other ones) and become more vulnerable to fire, so hunters could get alchemy/fire based skills/weapons. But vampires will get a skill to breathe underwater (alternatively water could hurt any vampire [as of level 1] unless they have this skill).
When choosing this path, vampire probably would not receive any damage from garlic, but rather be somehow disoriented.
This would mean hunters can mainly attack vampires using stakes, fire and (in the future) silver.
Vampires however would have a lot of health, teleport and other skills as well as strong close range attacks (bites or claws) and some kind of (more "magic") long range attack.

TODO:

• Make vampires more vulnerable to fire (284074a)
• Add fire based weaponry for Vampire Hunters
• Add ways to protect (decrease damage) yourself of fire as vampire
• Implement water weakness as well as skill to prevent this(#126)
• Change and extend garlic to mainly disorient vampires
• Garlic "Beacon" which weakens vampire around (No batmode as well). Expensive
• Update Guide Book accordingly

Still have to update the guide book, but everything else is implemented. Can be extended in the future of cause.