Table 1.
Pathogenicities of parental and chimeric viruses in embryonated eggs and chicks
| Virus | MDTa | ICPIb |
|---|---|---|
| rNDV | 57 h | 1.60 |
| rAPMV-2 | >120 h | 0.00 |
| rNDV/2 F-HN | >120 h | 0.00 |
| rAPMV-2/NDV F-HN | 64 h | 1.23 |
| rAPMV-2/NDV F | 120 h | 0.28 |
a
MDT, mean time (h) for the minimum lethal dose of virus to kill all of the inoculated embryos. Pathotype definition: virulent strains, <60 h; intermediately virulent strains, 60 to 90 h; avirulent strains, >90 h.
b
Pathogenicity of NDV in 1-day-old SPF chicks was evaluated by the ICPI assay. Pathotype definition: virulent strains, 1.5 to 2.0; intermediate virulent strains, 0.7 to 1.5; avirulent strains, 0.0 to 0.7.