Table 1. The hatchability, antibody response and protection rate of SPF chickens in-ovo vaccinated with different doses of NDV strains.
| Vaccines | Immunizationa | Challengeb | ||||||
|---|---|---|---|---|---|---|---|---|
| Dosage (log10 EID50) | Eggs | % hatched | % survivalc | HI titerd (log2) | Age at challenge (days post-hatch) | Chickens | Protection rate | |
| TS09-C | 4.0 | 30 | 96.7(29/30) | 93.3(28/30) | 4.2±0.79 | 21 | 10 | 100% |
| TS09-C | 3.0 | 30 | 96.7(29/30) | 93.3(28/30) | 3.9±0.99 | 21 | 10 | 100% |
| TS09-C | 2.0 | 30 | 96.7(29/30) | 90.0(27/30) | 3.3±0.95 | 21 | 10 | 100% |
| V4 | 2.0 | 30 | 66.7(20/30) | 23.3(7/30) | - | - | - | - |
| PBS | - | 30 | 96.7(29/30) | 90.0(27/30) | 0.0 | 21 | 10 | 0% |
aSPF chicken embryos were immunized with the different doses of vaccines or PBS in a 0.1 ml volume via the amniotic route at 18 embryo-days.
b10 SPF chickens selected randomly from each group were challenged with 104.0 EID50 NDV strain F48E9 at 21 days post-hatch.
cGlobal survival percent of SPF chickens at 5 days post-hatch.
dHI titers of sera collected from 10 SFP chickens in each group prior to challenge were expressed as log2 mean ± SD.