public health studies show a protective role of rabies virus vaccine against some diseases. The use of rabies virus vaccine as an immune therapeutic modality is in light of recent findings. This work described an inadequate antibody response to feline pan leukopenia vaccine in immunocompromised cats comparing with healthy one due to an underlying immunodeficiency condition. Healthy cats were immunocompromised using immunosuppressed drug then the cats received feline pan-leukopenia vaccine. Remissions occurred following injection of many doses of inactivated rabies vaccine in immunocompromised cats. The clinical studies showed that rabies virus vaccine injections enhanced immune response in vaccination of healthy and immunocompromised cats with feline panleukopenia vaccine. It could be concluded that inactivated rabies virus vaccine can be used as an immuno-stimulant.public health studies show a protective role of rabies virus vaccine against some diseases. The use of rabies virus vaccine as an immune therapeutic modality is in light of recent findings. This work described an inadequate antibody response to feline pan leukopenia vaccine in immunocompromised cats comparing with healthy one due to an underlying immunodeficiency condition. Healthy cats were immunocompromised using immunosuppressed drug then the cats received feline pan-leukopenia vaccine. Remissions occurred following injection of many doses of inactivated rabies vaccine in immunocompromised cats. The clinical studies showed that rabies virus vaccine injections enhanced immune response in vaccination of healthy and immunocompromised cats with feline panleukopenia vaccine. It could be concluded that inactivated rabies virus vaccine can be used as an immuno-stimulant.