Scientists Produce Cow Immune to Mad Cow Disease
Mon May 31, 2004 11:55 AM ET

TOKYO (Reuters) - Kirin Brewery Co, Japan's number-two beer maker, has succeeded in producing a cow that is immune to mad cow disease, but experts said it was too early for livestock producers to celebrate.
Kirin officials said on Monday the company had produced jointly with a U.S. company a cow that carried none of the "prion" proteins that cause the brain-wasting disease, also known as bovine spongiform encephalopathy (BSE).

BSE is passed on by an infectious protein particle called a prion. Neither a living organism nor a virus, it is a misshapen protein that can convert other proteins to the deadly form by touching them.

The animal, produced through genetic engineering, is still in its mother's womb and expected to be born early next year, Kirin officials said.