[Course of chronic brucellosis in mice is not improved by administration of a vaccinal antigen]

Of1 female Swiss mice inoculated with Brucella abortus virulent strain 544 since four weeks, were treated by subcutaneous injections of a B. abortus 19 cell-wall vaccine extracted by boiling sodium dodecylsulfate suspended in oil adjuvant (PG-B19). Vaccinations were administered at 10 or 100 micrograms dose per mouse, two to four times, at 15-30 days interval. Groups of six mice were killed at 4 week intervals up to 24 weeks post challenge to follow the evolution of splenic infections by enumeration of brucella. No significant changes were elicited by treatments. Since in this system, infections evolve spontaneously and progressively toward self-cure, an additional antigenic stimulation is unable to improve the immune response efferent arc.