In 1998 McNeil demonstrated that the adjuvant Rabies vaccines induced mutations on cell cultures at the 18th ACVIM. In 2001 McNeil demonstrated that adjuvant vaccines induced mutations of cell cultures but that non adjuvant vaccines did not. In 1999 the WHO (World Heath Organization) in Lyons, France declared that the veterinary vaccine adjuvant was a grade three out of four for being carcinogenic (cancer causing).