Vampires and Regeneration Options

[Melkor]

I'm working on a new Shadowrun campaign which is going to have some elements ispired by the movie "Underworld". I'm wanting to "adjust" the Vampires found in the Critters book to better match those from the movie. It will be my first Shadowrun game in YEARS, so I am not completely familiar with the rules, and wanted to ask for some assistance.

The current way Regeneration works (drawn together from the Critters book and the Shadowrun Companion) is that you roll when you receive deadly damage, and on a "1", you don't regenerate. This increases to a "1" or "2" in the event that some/all of the deadly damage received is from a source that the character is allergic to, or that causes massive tissue damage (fire, explosives, etc).

I would like a better way to represent the Vampires ability to be hurt by, but shrug off and later heal "normal" damage. I'm going to play around with letting the character's become infected at some point, and I would hate for a single roll of 1 or 1-2 to completely wipe out their character.

I considered giving the vampires complete immunity to "normal weapons", but they will also be wearing armor. Immunity gives the vampire an Armor Rating equal to his/her Essence Rating - add armor on top of that, and the vampires will almost NEVER take normal damage.....I want a happy medium.

Weapons based on Ultraviolet Light wouldn't automatically destroy the Vampire, but the would definitely bypass any kind of immunity.

Any ideas for making this work ? Thanks!