Attempts to protect rabbits against challenge with virulent, cell-associated, malignant catarrhal fever virus.

Rabbits hyperimmunized with inactivated malignant catarrhal fever virus (MCFV) infected rabbit lymph node cells did not develop specific antibodies to the virus and succumbed to challenge with live MCFV-infected lymphoid cells. Rabbits hyperimmunized with either inactivated or live, cultured bovine kidney cells infected with MCFV developed antibodies to the virus, but also succumbed to challenge with live MCFV-infected rabbit lymphoid cells. Rabbits hyperimmunized with live cultured rabbit kidney cells infected with MCFV developed antibodies to the virus and resisted challenge with live MCFV-infected rabbit lymphoid tissues 47 weeks later. However, rechallenge of this group at 90 weeks post immunization resulted in the death of 2/4 rabbits suggesting a waning immunity.