title: The effect of a live Neospora caninum tachyzoite vaccine in naturally infected pregnant dairy cows.
abstract: Neosporosis, caused by the intracellular protozoan Neospora caninum, is a major cause of abortion and reproductive failure in cattle worldwide. The principal route of transmission of neosporosis is via in utero infection of the offspring. There is no effective prophylactic treatment or vaccine available against bovine neosporosis. A N. caninum NcIs491 isolate was examined for its ability to immunize and reduce abortions in naturally infected dairy cows under field conditions. N. caninum-seropositive pregnant dams were inoculated with 10(8) live tachyzoites during mid-term pregnancy. A total of 520 N. caninum seropositive dams were included in this study, of these, 146 were immunized and 374 cows served as a non-vaccinated control group. A significantly lower incidence of abortion was observed in vaccinated compared to non-vaccinated cows, 16 and 26% respectively (P=0.01), with a vaccine efficacy of 39%. However, the number of seropositive offspring remained similar in both groups. Overall, this field trial suggests that vaccination with live N. caninum tachyzoites should be considered as an effective measure to reduce abortions caused by neosporosis in naturally infected cows.
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, Bet Dagan, 50250, Israel; Department of Microbiology and Molecular Genetics, the Kuvin Centre for the Study of Infectious and Tropical Diseases, the Hebrew University of Jerusalem, Jerusalem, Israel. Electronic address: monica@int.gov.il.
authors.forename: M L
authors.initials: ML
authors.lastname: Mazuz
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, Bet Dagan, 50250, Israel.
authors.forename: L
authors.initials: L
authors.lastname: Fish
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, Bet Dagan, 50250, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Wolkomirsky
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, Bet Dagan, 50250, Israel.
authors.forename: B
authors.initials: B
authors.lastname: Leibovich
authors.affiliation: Mutual Society for Insurance and Veterinary Services, Hahaklait, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Reznikov
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, Bet Dagan, 50250, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Savitsky
authors.affiliation: Department of Microbiology and Molecular Genetics, the Kuvin Centre for the Study of Infectious and Tropical Diseases, the Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: J
authors.initials: J
authors.lastname: Golenser
authors.affiliation: Division of Parasitology, Kimron Veterinary Institute, Bet Dagan, 50250, Israel.
authors.forename: V
authors.initials: V
authors.lastname: Shkap
mesh_terms: D000034:Abortion, Veterinary / Q000469:parasitology / Q000517:prevention & control*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000517:prevention & control*; D003048:Coccidiosis / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D007557:Israel; D018688:Neospora / Q000276:immunology*; D011247:Pregnancy; D016052:Protozoan Vaccines / Q000627:therapeutic use*; D014611:Vaccination / Q000662:veterinary*; D014613:Vaccines, Attenuated / Q000627:therapeutic use
chemical_list: D016052:Protozoan Vaccines; D014613:Vaccines, Attenuated
keywords: Abortion; Control; N. caninum; Neosporosis; Vaccination