immune suppressive effect of Marek's Disease virus vaccine [Rispen strain] on the immune response of chickens to New Castle Disease virus vaccine

ABSTRACT

In the present study the effect of MDV vaccine Rispen Strain [R-MDV] on the immune response of chicken to NDV vaccine [Losota strin] was studied. 3 major components were determined humoral immunity, cell mediated immunity and macrophage function. The obtained results revealed that MDV vaccine [R-MDV] has a clear immunosuppressive effect manifested by significant depression of antibody production to NDV, decrease in the number of ASC in the spleens of MDV vaccinated chicks, slight influence of the total serum protein with decrease in globulin percentage, significant depression in lymphocyte blastogenesis induced by PHA, decrease in macrophage activity and percentage, slight changes in the weight of lymphoid organs and clear reduction in the protection rate as measured by intramuscular challenge with velogenic viscerotropic strain of NDV