The VP-2 genes of canine parvovirus (CPV) and a recombinant consisting of CPV and feline panleukopenia virus (FPV) sequences were cloned into baculovirus expression vectors, fused to the baculovirus polyhedrin promoter. Recombinant baculoviruses were prepared and the properties of the parvovirus proteins expressed in insect cells examined. The proteins produced were the same size as the authentic CPV VP-2 protein, and were produced late after infection; the quantity of proteins recovered from the insect cell cultures was similar to those produced in CPV infections. Parvovirus particles formed had the haemagglutination (HA), sedimentation and buoyant density properties of authentic CPV capsids. Both the CPV capsids and the CPV-FPV recombinant capsids from the baculovirus system expressed the same epitopes as those seen in the viable parvoviruses when tested with a panel of antiparvovirus monoclonal antibodies. Lysates of recombinant baculovirus-infected cells were inoculated into dogs, giving rise to serum neutralizing and HAinhibiting antibodies, and the immunized dogs were protected from clinical disease upon challenge with a virulent isolate of the most recent antigenic type of CPV.

The authors present an epizootiological analysis of myxomatosis in Poland. The biological, physical and chemical properties of virus strains used for the production and control of 'Myxovac M' vaccine are discussed. The longterm stability, safety and efficacy of the vaccine are demonstrated. Laboratory experiments were confirmed in large-scale field observations.

No abstract

No abstract