Bacterin-induced protection of turkeys against fowl cholera following infection with Bordetella avium.

Groups of Beltsville small white turkeys, passively immunized and not passively immunized against Bordetella avium, were challenged with live B. avium at 2 days of age. Birds not passively immunized developed severe bordetellosis with early onset, whereas passively immunized birds developed mild bordetellosis with late onset. Following convalescence, birds with and without exposure to B. avium were vaccinated against fowl cholera with a water-in-oil bacterin. The birds were given a homologous challenge with serotype A: 3 Pasteurella multocida. Although no difference in protection against fowl cholera was seen between vaccinated birds that were previously infected with B. avium and those that were not, survivability was better in birds given two doses rather than 1 dose of bacterin.