Susceptibility to infective agent.
Susceptibility depends on both species differences and within species protein sequence variations.
The possibility of human transmission of BSE no longer an open question. It is widely accepted that BSE can be transmitted to humans and indeed has occurred. Sc 's Biochemical properties of the prion protein make it possible to trace the likely cause and similarities of non-familial vCJDs . However, the vCJD pattern was similar to the BSE pattern. Scrapie is very common in sheep while TSE type diseases are very rare in humans.