Effectiveness of the strain 919 bovine ephemeral fever virus vaccine in the face of a real-world outbreak: A field study in Israeli dairy herds

Dan Gleser, Karen Spinner, Eyal Klement*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Bovine ephemeral fever virus (BEFV) is a globally spread arthropod-borne RNA virus that has significant economic impacts on the cattle industry. A live attenuated commercial BEF vaccine, based on the Australian BEFV strain 919, is widely used in Israel and other countries. A previous study has suggested the high effectiveness of this vaccine (ULTRAVAC BEF VACCINE™ from Zoetis®), but anecdotal reports of high BEF morbidity among vaccinated dairy herds in Israel casted doubt on these findings. To resolve this uncertainty, a randomized controlled field vaccine effectiveness study was conducted in Israel during a BEF outbreak which occurred in 2021. Eleven dairy herds were enrolled and monitored for BEF-associated morbidity and rumination alteration patterns using electronic monitoring tags (HR Tags, SCR® Dairy, Netanya, Israel). Four of the herds were naturally infected with BEFV during the outbreak, resulting in a total of 120 vaccinated and 311 unvaccinated subjects that were included in the effectiveness study. A mixed-effect Cox proportional hazard regression model was used to calculate the overall hazard ratio between vaccinated and unvaccinated cattle. This analysis demonstrated an average vaccine effectiveness of 60 % (95 % CI = 38 %–77 %) for preventing clinical disease. In addition, a non-statistically significant trend (p = 0.1) towards protection from mortality was observed, with no observation of mortality among the vaccinated groups compared to 2.61 % mortality (7/311) among the unvaccinated subjects. One hundred and thirty vaccinated and unvaccinated calves from affected and non-affected herds and with different status of morbidity were sampled and analysed by serum-neutralization test. The highest titers of BEFV-neutralizing antibodies were found in subjects that were both vaccinated and clinically affected, indicating a booster effect after vaccination. The results of the study provide evidence for the moderate effectiveness of the ULTRAVAC BEF VACCINE™ for the prevention of BEF.

Original languageAmerican English
Pages (from-to)5126-5133
Number of pages8
Issue number35
StatePublished - 7 Aug 2023

Bibliographical note

Funding Information:
This research was funded by grant number #1211-0023 of the Chief scientist of the Israeli Ministry of Agriculture. In addition, we thank the ‘Hachaklait’ (non-profit veterinary organization owned by the farmers) and their veterinary practitioners, specifically DR. Gabriel Kenigswald and DR. Maor Kedmi, for their support in implementing the study. We also wish to thank Mr. Dani Kolber and Mr. Tsur Hadar from SCR® for providing essential rumination data and Mrs. Edna Galanti of the Israel Cattle Breeders Association for data regarding the study cattle population.

Publisher Copyright:
© 2023 Elsevier Ltd


  • Arbovirus
  • Dairy cows
  • Neutralizing antibodies
  • Randomized controlled field study
  • Rumination and activity monitoring tag
  • Vaccine effectiveness


Dive into the research topics of 'Effectiveness of the strain 919 bovine ephemeral fever virus vaccine in the face of a real-world outbreak: A field study in Israeli dairy herds'. Together they form a unique fingerprint.

Cite this