ABSTRACT
In this study we use 20 sheep divided into four groups [one group was injected with the vaccine, the second was taken the vaccine and ampicillin, the third group was taken the vaccine and cephalosporin and the fourth act as a control]. The immunity was measured humoral immunity to sheep pox virus vaccine by neutralization test and cell mediated immunity by lymphocyte transformation assay as well as phagocytosis. The results revealed that an increase of the immune status in group injected with antibiotics with vaccine than that received the vaccine only and than the control group. There were an increase of lymphocyte transformation test, neutralization test and phagocytosis. It could be concluded that ampicillin and cephalosporin directly increase the immune status in sheep vaccinated with sheep poxvirus vaccine