Like everything else about JW's, their opposition to vaccination is convoluted......
Vaccines can be divided into two basic categories
Pre-exposure vaccines (Poliomyelitis MMR, Varicella, Annual flu shots etc.) are precautionary. In other words, they are administered just in case you might someday be exposed to the disease in question. These types of vaccines are not derived directly from animal blood. The viral agent that forms the basis for the vaccine is usually cultured in egg. The most effective pre-exposure vaccines contain a live attenuated (weak) strain of the virus. When an attenuated strain is not available, the virus is chemically inactivated (killed) usually so that its RNA is completely destroyed and only the protein shell remains.
Although the body?s response to a live virus will usually be stronger, either way, it will react basically the same as if it were attacked by the real thing. Over the next few weeks it will produce antibodies against the virus, giving you long-term active immunity.
There are several ways pre-exposure vaccines have been administered. The smallpox vaccine was applied to the skin, usually high on the upper arm. The Sabin poliomyelitis vaccine (OPV) is given orally. Others are simply injected.
Jehovah?s Witnesses retracted their earlier opposition to vaccines in general in 1952, although they continued to describe them in negative terms for years. (The Watchtower December 15, 1952 p. 764)
However Jehovah's Witnesses continued to condemn a second type of vaccine even after 1952:
Post-exposure vaccines are reactionary. They are administered after you have already been exposed to the disease. Suppose you step on rusty nail and its been more than five years since your last tetanus booster. Suppose you are bitten by a rabid animal. You need immediate passive immunity.
Post-eposure vaccines contain immune-globulin, a plasma protein derived from blood. Although some common immune-globulins are produced recombinately today, formerly, the only source was some other creature that had already been exposed. It was common to use horses and other large animals, and for exotic diseases and antivenins against unusual snake and spider bites, it still is.
The immunity provided by post-exposure vaccines is very temporary
Jehovah's Witnesses ruled that post-exposure vaccines like the tetanus booster and the diphtheria anti-toxin were a matter of conscience in 1958. (The Watchtower, September 15, 1958 p. 575)
When transfusion became a disfellowshipping offense in 1961, they waffled back for the next few years (1961-1963) but finally declared post-exposure vaccines to be a matter of conscience again in 1964. (The Watchtower November 15, 1964 pp. 680-683)
