Immunity against prions?

Several recent reports indicate that antibodies directed against the cellular 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 pathogenesis in vivo. These findings suggest that immunotherapeutical intervention against prion diseases is not unattainable. Will vaccines and post-exposure strategies based on antibodies ever prove useful against scrapie, bovine spongiform encephalopathy (BSE), or Creutzfeldt–Jakob disease?