Research on prions and prion diseases has resulted in differing theories regarding prion infections. Some researchers continue to dispute the protein hypothesis of prions as infective proteins and insist that some type of virus is the culprit. However, the majority of research throws some doubt on this since it is difficult to isolate DNA and RNA material in infected samples, which is not the case in known viral and bacterial infections. In addition, there is no immune response to an infection.
