The Strain Wiki
"The undead returning for their Dear Ones. Human love corrupted into vampiric need." Dr. Nora Martinez

Albania, 1971: Miriam Setrakian, newly turned, returns with her two children, to infect her husband, Abraham.

According to Abraham Setrakian, one of the most perverse effects of the vampire virus is that humans who have recently been infected are driven by a primal need to infect their closest friends and family members first.

"Once turned, the revenants first seek out family and friends still uninfected. They return, by night, to those with whom they share an emotional attachment. Their ‘Dear Ones.’ Like a homing instinct, I suppose. The same animal impulse that guides lost dogs hundreds of miles back to their owners. As their higher brain function falls away, their animal nature takes over. These are creatures driven by urges. To feed. To hide. To nest."

A recently-turned vampire's "Dear Ones" are in foremost danger of being infected first, due to their close relation, love, rapport and affinity they shared with the vampire in life. Unlike other vampiric attacks, the urge to infect "Dear Ones" is not primarily motivated by the need for sustenance (i.e., bloodlust).

In order to avoid this impulse, The Ancients, including The Master, deliberately choose as hosts human beings who have no living relatives or close friends.