A notable member of this forum tipped me off to this fact, and I recently checked up on it.
Check out the CDC's ingredient list for vaccines:
http://www.cdc.gov/vaccines/pubs/pinkbook/downloads/appendices/B/excipient-table-2.pdf
Any vaccine you see with the ingredients "bovine Albumin", "bovine Serum", "human serum albumin", are made from blood!
This includes all the standard childhood vaccinations such as measles, mumps, rubella, and even rabies.
Some of these vaccines are said to contain bovine or human serum. If I'm not mistaken, this would indicate that whole blood PLASMA minus the clotting factors are used.
The WTS has described "blood fractions" in its literature without mentioning this glaring detail!