Table 3. Virus neutralizing activity of immune sera from SPF chickens following vaccination with either VRPs, inactivated virus, or live attenuated virus.
| Virus neutralization titers (ND50/ml) following immunization witha | |||||
| Virus | Clade | VSV*ΔG (HAH5-HP) | VSV*ΔG (HAH5-LP) | Inactivated Vac-1/04 (H5N1) | Live Vac-1/04 (H5N1) |
| A/Vietnam/1194/2004 (H5N1) | 1 | 2'260 | 2'260 | 560 | <100 |
| A/chicken/Yamaguchi/7/2004 (H5N1) | 2.5 | 12'800 | 1'350 | 670 | <100 |
| A/whooper swan/Mongolia/3/2005 (H5N1) | 2.2 | 6'400 | 1'350 | 470 | <100 |
| A/Cygnus olor/Italy/742/2006 (H5N1) | 2.2 | 10'800 | 4'550 | 280 | <100 |
| A/duck/Hokkaido/Vac-1/2004 (H5N1) | - | 21'300 | 72'800 | 72'400 | 21'500 |
| A/duck/Potsdam/1402/1986 (H5N2) | - | 9'050 | 30'800 | 6'400 | 800 |
| A/duck/Potsdam/2216/84 (H5N6) | - | 5'400 | 21'300 | 4'530 | 1'130 |
| A/duck/Potsdam/619/85 (H5N2) | - | 10'750 | 36'200 | 21'520 | 2'260 |
| A/ostrich/Germany/R5-10/03 (H5N2) | - | 16'400 | 15'750 | 21'280 | 1'640 |
| A/mallard/Föhr/Wv1310-13/03 (H5N2) | - | 10'800 | 18'100 | 9'050 | 960 |
| A/teal/Föhr/Wv1378-79/03 (H5N2) | - | 3'800 | 6'400 | 21'528 | 1'340 |
a
SPF chickens were immunized with four different vaccines.
VSV*ΔG(HAH5-HP) and VSV*ΔG(HAH5-LP) were applied intramuscularly without adjuvant using 2×108 ffu for both the primary and booster immunization. Inactivated A/duck/Hokkaido/Vac-1/04 (H5N1) was formulated with adjuvant and applied two times via the intramuscular route. Live A/duck/Hokkaido/Vac-1/04 (H5N1) was applied one time via the intratracheal route using 107 TCID50. Serum was prepared from 4 to 5 animals per group and pooled. Virus neutralization tests were performed with the viruses listed in the left column. Neutralization titers obtained with homologous virus are underlined.