The invention relates to the use of an agent such as an antibody capable of reacting with PrP in the prevention of prion replication in a subject, in the treatment or prevention of prion infection, in the treatment or prevention of neuropathology associated with prion infection or in the preparation of a medicament for the treatment or prevention of prion disease. Furthermore, the invention relates to methods of treatment of prion disease, methods of inhibiting prion replication and antibodies for use in such methods.