Actually, he just wants transfusions from the young and healthy, the history of which is discussed
here by Candida Moss:
Peter Thiel, billionaire tech investor, has revealed a somewhat unsavory interest in the blood of the young. Thiel, like many other Silicon Valley billionaires, is interested in prolonging life expectancy and escaping death. ... Thiel has a particular interest in medical vampirism. ... Now he is interested in parabiosis, the practice of using blood transfusions from young people to promote longevity.
Read the rest of the story and you will get the sense that from the perspective of the Jewish law at least, the development of the Christian idea of drinking Christ's blood in the communion and the fascination among the wealthy with drinking the blood of the executed represents the sweep of history as degenerate, reverting to pagan antitypes, not progressive. The barbarity of animal sacrifice for sin remains, nothwithstanding.
But flesh with the life thereof, which is the blood thereof, shall ye not eat.
-- Genesis 9:4
For the life of the flesh is in the blood: and I have given it to you upon the altar to make an atonement for your souls: for it is the blood that maketh an atonement for the soul.
-- Leviticus 17:11
For it is the life of all flesh; the blood of it is for the life thereof: therefore I said unto the children of Israel, Ye shall eat the blood of no manner of flesh: for the life of all flesh is the blood thereof: whosoever eateth it shall be cut off.
-- Leviticus 17:14
Only be sure that thou eat not the blood: for the blood is the life; and thou mayest not eat the life with the flesh.
-- Deuteronomy 12:23
Then Jesus said unto them, Verily, verily, I say unto you, Except ye eat the flesh of the Son of man, and drink his blood, ye have no life in you.
-- John 6:53