TABLE 1.
Neutralization activity induced by recombinant VPX and VP3
| Serum | Neutralization titera
|
|
|---|---|---|
| Anti-SAL-1 | Anti-OH-2 | |
| Rabbit anti-VPX tubules | 12,800 | 100 |
| Rabbit anti-VP3 | <50 | <50 |
| Preimmune rabbit serum | <50 | <50 |
| Serum from D78-vaccinated chickens | 3,200 | <50 |
| Serum from IBDV-free chickens | <50 | <50 |
a
Each neutralization titer is the reciprocal value of the highest dilution of the corresponding antiserum that causes a 50% reduction of the cell monolayer in a protection assay described in Materials and Methods. Pooled serum from chickens vaccinated with the D78 strain was included as a positive control. Sera from preimmune rabbits and IBDV-free chickens were used as negative controls. Sera were inactivated for 30 min at 56°C to remove any complement activity.