Actually, better quotes (especially remember the "filthy pus") from jwfacts
http://www.jwfacts.com/watchtower/medical.php#vaccinations
Vaccinations
From 1921 to 1952, the Golden Age presented information against vaccinations. To cement this viewpoint in the minds of followers, vaccinations were described as worthless, harmful from a medical standpoint, and morally wrong from a biblical standpoint.
"Vaccination never prevented anything and never will, and is the most barbarous practice...We are in the last days; and the devil is slowly losing his hold, making a strenuous effort meanwhile to do all the damage he can, and to his credit can such evils be placed. ... Use your rights as American citizens to forever abolish the devilish practice of vaccinations." Golden Age 1921 Oct 12 p.17
"Thinking people would rather have smallpox than vaccination, because the latter sows the seed of syphilis, cancers, escema, erysipelas, scrofula, consumption, even leprosy and many other loathsome affections. Hence the practice of vaccination is a crime, an outrage and a delusion." Golden Age 1929 May 1 p.502
"Avoid serum inoculations and vaccinations as they pollute the blood stream with their filthy pus." Golden Age 1929 Nov 13 pp.106-107
This was partially supported on the basis that blood byproducts could not be used.
"Vaccination is a direct violation of the everlasting covenant that God made with Noah after the flood." Golden Age 1931 Feb 4 p.293
"Of all the inventions that have been foisted upon mankind for their defilement the most subtly devilish is that of vaccination." Ibid p.295
The Golden Age 1931, February 4 issue devoted 10 pages to why vaccinations were not for Christians. The index page to the 1931 article claimed this as the viewpoint of the Creator.

A series of images further enforced the point.

Golden Age 1932 Mar 30 p.409

Golden Age 1939 May 31 p.5
The cartoon picture above shows dead and pock marked babies below a clergy like representation. In reality, it was vaccinations that practically eliminated small pox. With little medical knowledge, the society went about using scare tactics to convince the people that vaccinations were wrong. This resulted in some Witness children being barred from schools in America for refusing vaccinations.
Legal concerns seem to be a factor behind the Watchtower Society reversing its position and allowing vaccinations from the 1950's.
"The matter of vaccination is one for the individual that has to face it to decide for himself... And our Society cannot afford to be drawn into the affair legally or take the responsibility for the way the case turns out." Watchtower 1952 Dec 15 p.764
Did Holy Spirit direct the Society to decree vaccinations were unchristian for a period of time, and later say they were acceptable? For followers who are trained to accept everything coming from the Organization as food from Jehovah, this has potentially led to needless loss of Witness lives.
In 1993 the following was written, and whilst strictly correct it can be understood in light of what appears above to be quite misleading.
"Previous articles in this journal and its companion, The Watchtower, have presented a consistent position: It would be up to the Bible-trained conscience of the individual Christian as to whether he would accept [vaccinations] for himself and his family." Awake! 1993 Aug 8 p.25