According to lore, they have to be invited in. Within the sacred space of your home, they can not harm you. They can not suck one drop of your precious life-giving blood unless you open the door and invite them past your threshold.
If your time, your attention, and your purpose are not the very essence of what life is, then what is? If where you commit your time, attention, and purpose is not sacred space, then why isn't it? And if those items that seek to take from those things are not vampires, then what are they?
Most importantly, why are you inviting them in?