TABLE 1.

Comparison of pathogenicities of rMd5, rMd5/ΔvIL-8, rMd5/vIL-8-ELR, and rMd5/ΔvIL-8-RV in 15 × 7 MDV maternal antibody-negative chickensa

VirusbNo. of chickens that died/no. tested (%)No. of chickens with tumor/no. tested (%)
Mock0/17 (0)0/17 (0)
rMd515/17 (88.2)13/17 (76.7)
rMd5/ΔvIL-81/17 (4.3)*3/17 (17.6)*
rMd5/vIL-8-ELR16/17 (94.1)15/17 (88.2)
rMd5/ΔvIL-8-RV17/17 (100)13/17 (76.7)
  • a This experiment was repeated two times separately. *, Student's t test (P ≤ 0.001) analysis indicated value was significantly different from those for the other groups.

  • b All chickens were inoculated with 2,000 PFU of the indicated viruses.