I researched this a few years ago. Here are some notes I made; hope it helps. It morphs from anti-vaccination to anti-transfusion.
“Instead, we should write to them to keep away from things polluted by idols, from sexual immorality, from anything strangled, and from blood. After all, Moses has had people to proclaim him in every city for generations, and on every Sabbath his books are read aloud in the synagogues.” – Acts 15:20,21, ISV
1909
"These prohibitions had never come to the Gentiles, because they had never been under the Law Covenant; but so deeply rooted were the Jewish ideas on this subject that it was necessary to the peace of the church that the Gentiles should observe this matter also." – Zion’s Watch Tower April 15, 1909
1931
“The most sacred thing on earth in the sight of God is human blood, “for in the image of God he made man.” (See Genesis 9:6.) God destroyed the entire human race, except Noah and his family, at the time of the flood, because of un-natural pollution of human blood.”
“So important was this covenant that God placed His bow in the clouds as an everlasting reminder of the danger of its violation.”
“What about Armageddon?…Will those who have made and injected and suffered the injection of calf and horse serums [for vaccination] into the human bloodstream go scot free? We doubt it.”
“Quite likely there is some connection between the violation of human blood and the spread of demonisim.”
“…much of the looseness of our day along sexual lines may be traceable to the easy and continued violation of the divine commands to keep human and animal blood apart from each other. With cells of foreign blood racing through his veins man is not normal, not himself, but lacks the poise and balance which make for self control.” – The Golden Age, February 4, 1931
1954
"We are told that it takes one and a third pints of whole blood to get enough of the blood protein or "fraction" known as gamma globulin for one injection... its being made of whole blood places it in the same category as blood transfusions as far as Jehovah's prohibition of taking blood into the system is concerned." - Awake!, January 8, 1954 p.24
1961
"The blood in any person is in reality the person himself. ... poisons due to personal living, eating and drinking habits ... The poisons that produce the impulse to commit suicide, murder, or steal are in the blood. Moral insanity, sexual perversions, repression, inferiority complexes, petty crimes - these often follow in the wake of blood transfusion." - Watchtower, September 1, 1961 p.564