It faces many obstacles including hyperacute rejection, retroviral infections, transfer of prions, and severe side-effects of immunosuppressive drugs. Moreover, animal and human organs differ in their anatomy, production of hormones, secretion and absorption of enzymes and other chemicals, in their resistance to disease, and longevity. Despite almost 100 years of experimentation, no human has ever survived an animal organ transplant. Hundreds of thousands of gruesome xenotransplant experiments in animals have failed to tell us how xenografts will perform in people. The safety and efficacy of animal cell transplants for conditions like Parkinson's Disease, epilepsy, and diabetes have yet to be proven.
Many questions have yet to be answered.
These questions should figure prominently in current bioethics debates, and the public should be invited to participate. Until then, public interest groups like ours will continue to campaign for a ban on all uses of xenotransplantation.