Effect of vaccination with a monovalent Leptospira interrogans serovar hardjo type hardjo-bovis vaccine on type hardjo-bovis infection of cattle.
Effectiveness of 2 concentrations of a monovalent vaccine containing Leptospira interrogans serovar hardjo type hardjo-bovis was evaluated for protection of heifers from infection with type hardjo-bovis. Nine heifers were given 2 doses of low-dose vaccine (8.32 x 10(8) cells/dose); 9 heifers were given 2 doses of high-dose vaccine (8.32 x 10(9) cells/dose); and 1 steer and 1 heifer were maintained as nonvaccinated controls. Groups of vaccinated cattle were challenge-exposed with serovar hardjo type hardjo-bovis at 7 (n = 6), 11 (n = 6), or 15 (n = 6) weeks after completion of vaccination. All cattle were challenge-exposed by conjunctival instillation of 1 x 10(5) hardjo-bovis cells on 3 consecutive days. Both control and all vaccinated cattle became infected and shed serovar hardjo type hardjo-bovis in their urine. Leptospires were detected in 15 of 16 (94%) urine samples from control cattle and in 124 of 143 (87%) samples from vaccinated cattle. Leptospires were detected in kidneys of 17 of 18 vaccinated cattle and 2 of 2 control cattle and in the uterus or oviducts of 13 of 18 vaccinates and the 1 control heifer.
Bolin
C A
CA
Leptospirosis Mycobacteriosis Research Unit, National Animal Disease Center, USDA, Ames, IA 50010.
Cassells
J A
JA
Zuerner
R L
RL
Trueba
G
G
D000372:Agglutination Tests; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001428:Bacterial Vaccines; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D005187:Fallopian Tubes / Q000382:microbiology; D005260:Female; D005455:Fluorescent Antibody Technique; D007124:Immunoenzyme Techniques; D007668:Kidney / Q000382:microbiology; D007921:Leptospira interrogans / Q000276:immunology* / Q000302:isolation & purification; D007922:Leptospirosis / Q000517:prevention & control / Q000662:veterinary*; D008297:Male; D014599:Uterus / Q000382:microbiology; D014611:Vaccination / Q000662:veterinary*
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines