[Local and systemic immunization against experimental infection of mice with Pasteurella multocida].

Model experiments with mice are presented in which the defense against challenge infections has been checked after immunization with various living and killed vaccines of Pasteurella. A temperature sensitive Pasteurella mutant has proved to be superior to inactivated bacteria. It has been established that different routes of administration result in different effects. In this context, intraperitoneal, intramuscular and intratracheal administration have resulted in the highest protection rates, even when combined with oral and aerogeneous immunizations, which are of little efficacy when used exclusively. The importance of a change in the route of administration during repeated immunizations is discussed.