Pasteurella multocida: antibody-mediated resistance to virulent challenge exposure in vaccinated turkeys.

Aspects of antibody-mediated resistance to Pasteurella multocida infection in vaccinated turkeys were investigated. Pasteurella immune serum obtained from vaccinated turkeys was shown to confer temporary protection to nonvaccinated turkey poults. Recipients given immune serum were free of clinical signs of disease for at least 8 days after IM challenge exposure with virulent P multocidae 1059. All turkeys given normal serum died within 36 hours of challenge exposure. Vaccinated bursectomized turkeys were more susceptible to IM challenge exposure than were vaccinated nonbursectomized turkeys. In two of three trials, mortality also occurred earlier in the bursectomized groups when compared with mortality in the control groups. The presence of specific antibody may be an important determinant in resistance to Pasteurella infection.