Abstract
Pretreatment with H. pertussis vaccine increased the resistance of white mice to a challenge of approximately 100 LD50 of a moderately virulent strain of Bacterium tularense. [Pasteurella tularensis]. Simultaneous inoculation of H. pertussis vaccine and living B. tularense increased the susceptibility to infection with the latter. The combination of H. pertussis with B. tularense vaccine improved the efficacy of the latter to low challenge doses. The value of H. pertussis vaccine as an adjuvant was discussed.