Antigens characteristic of an organ or tissues are called
organ-specific antigens. These antigens found in the brain, kidney, and lens
tissues, even of different animal species, share the same antigen specificity.
Organ-specific antigens, such as brain-specific antigens, shared by human and
sheep brain are one such example. The antirabies vaccines prepared from sheep
brain, when given, may induce immune response in some humans, causing damage to
neural tissues of the recipient. This may result in neuroparalytic
complications in some individuals.