Figure 1.

Schematic of experiments performed to test the effect of CD8 T cell on MD and vaccinal protection. Chicks were vaccinated with SB-1, HVT, or bivalent SB-1+HVT vaccine on the day of hatch, and later injected with PBS only or purified 1 mg of anti-CD8 mAB on 1, 3, and 4 days post-vaccination (DPV). Chickens were challenged with Md5 pathogenic MDV 5 DPV. One mg of anti-CD8 mAb was administered weekly to deplete chicken CD8 T cells until 8 weeks post challenge. Percent MD was determined based on MD pathology including nerve lesions and tumor development.