Table 6.
Protective effects in 3-week-old SPF chickens immunized with H120 and K2p170 against challenge with IBV isolates representing the two major Korean IBV genogroups.
| IBV strain immunizeda | Genogroup of challenge virus | IBV strain of challenge virusb | No. of challenge virus isolated/no. of challengedc |
|||
|---|---|---|---|---|---|---|
| Trachea |
Kidney |
|||||
| Control | Vaccinated | Control | Vaccinated | |||
| H120 | Korean group I | Mass 41 | 10/10 | 0/10*** | 10/10 | 0/10*** |
| K571/99 | 9/10 | 5/10 | 1/10 | 0/10 | ||
| K107/04 | 7/10 | 4/9 | 0/10 | 0/9 | ||
| Korean group II | K2parent | 10/10 | 3/10** | 10/10 | 7/10 | |
| KM91 | 10/10 | 5/10 | 8/10 | 4/10 | ||
| K1277/03 | 10/10 | 8/10 | 9/10 | 8/10 | ||
| K2p170 | Korean group I | Mass 41 | 10/10 | 2/10*** | 10/10 | 0/10*** |
| K571/99 | 9/10 | 0/10***,† | 1/10 | 1/10 | ||
| K107/04 | 7/10 | 2/10 | 0/10 | 0/10 | ||
| Korean group II | K2parent | 10/10 | 1/10*** | 10/10 | 1/10***,† | |
| KM91 | 10/10 | 4/10* | 8/10 | 0/10*** | ||
| K1277/03 | 10/10 | 3/8** | 9/10 | 0/8***,†† | ||
Three-week-old chickens were immunized with IBV, H120 and K2p170 (103.0EID50/bird) via the intraocular route.
At 3 weeks post-immunization, all birds were challenged with 104.5EID50 of six Korean IBV strains via the intraocular route.
Five days after challenge, protection was evaluated by the absence of challenge virus in the kidney and trachea.
p < 0.01, by Fisher's exact test, compared to non-vaccinated control group.
p < 0.005, by Fisher's exact test, compared to non-vaccinated control group.
p < 0.001, by Fisher's exact test, compared to non-vaccinated control group.
p < 0.01, by Fisher's exact test, compared to the H120-vaccinated group.
p < 0.005, by Fisher's exact test, compared to the H120-vaccinated group.