[Effect of allogeneic tumor extracts on the development in calves of an experimental infection by the bovine leukemia virus].

The allogenic tumour extracts were studied as immunogens for the prevention of cattle infection with BLV. Immunization did not induce both the production of antibodies against the virus and spontaneous viral infection. Experimental infection of immunized animals with living leukocytes of a leukemic donor caused a BLV infection in 100% of cases.