In October 1997, Stanley Prusiner, a professor at the
University of California–San Francisco who had spent twentyfive
years studying prions, went to Stockholm to receive the
prize he called “the big one” from the King of Sweden. His
great achievement was to show that the prion (pronounced
“pree-on”), the infectious agent responsible for bovine
spongiform encephalopathy, or mad cow disease, Creutzfeldt-
Jakob disease, and a disease in sheep called scrapie, was not a
virus or a bacterium but a protein, a nonliving thing. Protein,
as the name suggests, is prime, proto matter. (“These agents,”
one prion researcher told a documentary film interviewer, “are
almost immortal.”)