JOURNAL OF ACBKHLTIIRAL ISEARCfl 
Vol. XXVIII Washington, D. C., May 17, 1924 No. 7 
STUDIES RELATING TO THE IMMUNOLOGY OF BOVINE 
INFECTIOUS ABORTION 1 
By J. M. Buck and G. T. Creech, Pathological Division, Bureau of Animal 
Industry, United States Department of Agriculture 
INTRODUCTION 
Artificial immunization as a means of combating infectious diseases of the 
domestic animals is a subject that during recent years has received no little 
amount of consideration. Numerous diseases which formerly exacted heavy 
losses are now being more or less successfully suppressed through the utilization 
of immunizing substances. As a result of the progress made along these lines, 
persons interested in disease-control work have naturally been much encouraged 
and led to entertain hope that such methods of combating disease may in the 
course of time be greatly extended. 
REVIEW OF PREVIOUS WORK 
Investigators for a number of years have been interested in determining 
whether bovine infectious abortion may be advantageously attacked through 
the agency of biological preparations. The subject has been of especial interest 
in connection with this disease because of the fact that the control of Bacterium 
abortus exposure in infected herds is extremely difficult and because the total 
elimination of the infection from such herds frequently is accomplished only at a 
financial sacrifice which renders such an attempt impracticable. 
Efforts to evolve and evaluate biological methods of control have been prompted 
to a great degree by the observation that in recently infected herds the disease 
generally spreads rapidly and for a period causes excessive losses which, in 
the event that animals from other herds are excluded, show a tendency to gradu¬ 
ally subside, or in the course of time even largely to disappear. It has seemed 
reasonable to ascribe the improvement in conditions, in part at least, to the 
development of a naturally acquired immunity and to infer that a resistance of 
similar character should be possible of development in an artificial manner. 
Bang 2 in his early writings relative to the isolation of the abortion microor¬ 
ganism called attention to the possibilities of artificial immunization, and in a 
later report 3 recorded the results of his experiments in which both living and 
killed cultures of Bacterium abortus were employed. A practice was made of 
injecting nonpregnant animals either subcutaneously or intravenously a number 
of times and, following conception, subjecting them to a severe type of Bacterium 
abortus exposure. While many of his treated animals failed to withstand the 
degree of exposure to which they were subjected, the results obtained were never¬ 
theless encouraging, particularly those derived from the subcutaneous adminis¬ 
trations of living cultures. 
1 Received for publication Mar. 4, 1924. 
2 Bang, B.—Die Aetiologie des seuchenhaften (“InfectiOsen”) Vebwerfens. Ztschr. Thier- 
med. 1: 241-278, illus. 1897. 
2 Bang, B.— Infectious abortion in cattle. Jour. Compar. Path, and Ther. 19: 191-202. 1906. 
Journal of Agricultural Research, 
Washington, D. C. 
96037—24f-1 (607) 
Vol. XXVIII, No. 7 
May 17, 1924 
Key No. A—90 
