My archer, Stormarcher, daze hit herself, proc'ing poison arrow, then shot the mob, using vamp rune, and saw a 70(35) or so. She has 0 in the new skill.
I further tested duelihg Nibbles with my caster, Stormwizard, letting burning soul tick on him. Nibbles has the skill leveled to 19, and was fighting me @ full hp, using sacri. He and I saw no heals to stop the burning soul from happening, nor from a single disease or poison I tried later.
I then dueled Oprichniki, who has the skill @ 26, and uses stalkers and whips, and there was no cleanse during that duel against burning soul also. I was not attacking, just healing myself during both duels.
Skill is brokeded
Also, please make sure the skill does not double-dip...as vamps in bonus are based off the bonus damage multiplier, and cures are too, if the vamps get teh bonus, and the cure does also, that will basically eliminate dot damage if you vamp over your hp at all.
After further testing(dueling, dot'ing, then escaping, then starting PvE fight) it works PvE, just not PvP