Is the scrapie agent a virus?

Abstract

THE nature of the scrapie agent has been obscure for many years. It is not known whether it is a virus in a strict sense, some replicating agent which is devoid of nucleic acid^1,2, or a transmissible self-replicating cellular membrane^3,4. In previous experiments with the Chandler strain of the scrapie agent, numerous 14-nm virus-like particles were isolated⁵ from infected mouse brains using repeated fluorocarbon extraction procedures which have been used for the isolation of Aleutian disease virus from infected mink tissues^6,7. The present experiments were designed; first, to determine if similar 14-nm virus-like particles could be isolated from hamster brains infected with scrapie agent; and second, to determine if the 14-nm virus-like particles induce scrapie in mice and hamsters.