Immunity against prions?

Several recent reports indicate that antibodies directed against the cellul ar form of the prion protein, PrPc, might eliminate the transmissible agent of spongiform encephalopathies (the prion) from scrapie-infected cells in vitro, and that a humoral immune response could prevent scrapie pathogenesi s in vivo. These findings suggest that immunotherapeutical intervention aga inst prion diseases is not unattainable. Will vaccines and post-exposure st rategies based on antibodies ever prove useful against scrapie, bovine spon giform encephalopathy (BSE), or Creutzfeldt-Jakob disease?.