No, it only makes you untargetable, so if you pool at low health, you could die from the DoT.
Here's a quote from the LoL Wiki on it:
Vladimir is still affected by damage over time effects (like Ignite and Swain's Torment) while going into Sanguine Pool.
Source: http://leagueoflegends.wikia.com/wiki/Vladimir_the_Crimson_Reaper/Ability_Details
