Board Thread:Skyrim/@comment-108.220.168.70-20150624211339/@comment-108.201.2.96-20150726014439

Vampires will attack you regardless of status. It doesn't matter if you're one of them or are at stage 4, they will attack you. If you don't have Dawnguard installed, stage 4 can make things much harder for you. All NPCs around you will become hostile and will attack you, except for followers and guild members if you happen to be a member yourself.