title: The protective effectiveness of an inactivated bovine ephemeral fever virus vaccine.
abstract: Bovine ephemeral fever (BEF) is an important viral disease of cattle. Despite the extensive use of inactivated vaccines for the prevention of BEF, a controlled study of their field effectiveness has never been performed. We conducted a large field effectiveness study of a BEF inactivated vaccine, during a large BEF outbreak. Neutralizing antibody titers measured in 385 heifers and calves 1 month after 2(nd) vaccination averaged 1:91.8 (CI95%=76.6-110). The effectiveness study enrolled 2780 cows in nine herds. In two herds cows vaccinated twice, 1 year before the outbreak and once 2-3 months before outbreak onset were compared with non-vaccinated cows. Average vaccine effectiveness of three vaccine doses compared to no vaccination was 47% (CI95%=34-57) in these herds. In two other herds cows vaccinated twice 1 year before the outbreak and twice again 2-3 months before outbreak were compared with cows vaccinated only twice 2-3 months prior to the outbreak. Average vaccine effectiveness of four doses compared to two doses was 49% (CI95%=25-65) in these herds. In five herds cows vaccinated twice 2-3 months before outbreak onset were compared with non-vaccinated cows. This vaccination schedule was shown to be non-effective (average effectiveness=2%, CI95%=-14-17). Milk production analysis on one of the effected herds, in which 56% vaccine effectiveness and an absolute reduction of 27% in morbidity were documented, revealed a net milk production loss of 175.9kg/sick cow (CI95%=127.9-223.9) and an average gain of 37kg for each vaccinated cow (CI95%=-3.6-77.7). This study indicates that despite the fact that two vaccine doses of the tested inactivated vaccine elicited high titers of neutralizing antibodies, partial protection was induced only when at least 3 doses were administrated before natural challenge.
authors.affiliation: Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Israel.
authors.forename: Orly
authors.initials: O
authors.lastname: Aziz-Boaron
authors.affiliation: Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Gleser
authors.affiliation: Kimron Veterinary Institute, Israel.
authors.forename: Hagai
authors.initials: H
authors.lastname: Yadin
authors.affiliation: Kimron Veterinary Institute, Israel.
authors.forename: Boris
authors.initials: B
authors.lastname: Gelman
authors.affiliation: Hachaklait Veterinary Services, Israel.
authors.forename: Maor
authors.initials: M
authors.lastname: Kedmi
authors.affiliation: Israel Veterinary Services, Israel.
authors.forename: Nadav
authors.initials: N
authors.lastname: Galon
authors.affiliation: Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Israel. Electronic address: eyal.klement@gmail.com.
authors.forename: Eyal
authors.initials: E
authors.lastname: Klement
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000032:analysis; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D004196:Disease Outbreaks; D004810:Ephemeral Fever / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D018115:Ephemeral Fever Virus, Bovine / Q000276:immunology*; D005260:Female; D007115:Immunization Schedule; D007557:Israel / Q000453:epidemiology; D008297:Male; D014611:Vaccination / Q000662:veterinary*; D015164:Vaccines, Inactivated; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D015430:Weight Gain
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D015164:Vaccines, Inactivated; D014765:Viral Vaccines
keywords: Bovine ephemeral fever; Efficacy; Immunological memory; Inactivated vaccine; Vaccine effectiveness; Vaccine non responsiveness