Vampires incur sun damage if outdoors during daylight, and do not regenerate Health while resting. After three days the victim's body is overwhelmed and must live as a vampire. It may also be obtained from searching corpses. Vampirism is a disease that can be contracted during melee combat with anyone who is infected. Vampirism is a unique magic effect and an ability in The Elder Scrolls III: Morrowind that is a member of the Destruction school of magic, governed by Willpower.
'This effect confers upon a subject all the abilities and weaknesses of the disease called vampirism.' ― The Elder Scrolls III: Morrowind Construction Set