Studies on the Immunization of White Mice Against Infections with Bacterium Tularense

• Published in: The Journal of immunology (1950) Vol. 69; no. 5; pp. 515 - 524
• Main Authors: Frederick Bell, J, Larson, Carl L, Wicht, W. C, Ritter, Sara S
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01-11-1952
• Subjects: Animals; Francisella tularensis; Immunization; Mice; Old Medline; Vaccination; PASTEURELLA TULARENSIS
• DOI: 10.4049/jimmunol.69.5.515
• EISSN: 1550-6606
• ISSN: 0022-1767

The successful immunization of white mice against challenge with Bacterium tularense is described. The immunization procedure consisted of a single intraperitoneal injection of 0.1 ml of an ether-extracted vaccine. Four strains of B. tularense differing markedly in virulence were of equal potency when used as vaccines. The mice should be at least 40 days old when vaccinated.
Considerable immunity was apparent when the mice were subsequently challenged subcutaneously with serial 10-fold dilutions of a strain of B. tularense which possessed full virulence for mice but diminished virulence for rabbits. The protection conferred upon immunized mice was measured by the differences in LD50 titers of the control and vaccinated groups of mice.