Table 1. Protections conferred in chickens vaccinated with the vaccine formulations upon challenge exposure with 100 LD50 of live P. multocida strain X-73.
| Group | Vaccine formulation (per dose) | Route | No. of immunizationsa) | No. of survivors / challenged (% protection) |
|---|---|---|---|---|
| 1 | 50 µg rOmpH + 10 µg ODN | IN b) | 19 | 9/10 (90)d) |
| 2 | 50 µg rOmpH + 3 µg LTB | IN | 19 | 7/10 (70)d) |
| 3 | 100 µg rOmpH + Freund’s incomplete | IM c) | 19 | 10/10 (100)d) |
| 4 | DLD bacterin e) | IM | 14 | 5/5 (100)d) |
| 5 | 10 µg ODN | IN | 14 | 0/5 (0) |
| 6 | 3 µg LTB | IN | 14 | 0/5 (0) |
| 7 | 50 µg rOmpH | IN | 14 | 0/5 (0) |
a) Three chickens were collected from each group for the tracheal lavage on days 0, 14 and 28. b) Intranasal administration at 60 µl per dose. c) Intramuscular administration at 1 ml per dose. d) Statistically significant as compared with the control groups, P<0.05. e) The DLD bacterin vaccine is a bacterin vaccine which manufactured by the Bureau of Veterinary Biologics, Department of Livestock Development, Ministry of Agriculture and Cooperatives, Thailand.