|Walz, Paul - Auburn University|
|Riddell, Kay - Auburn University|
|Newcomer, Benjamin - Auburn University|
|Cortese, Victor - Zoetis|
|Scruggs, Daniel - Zoetis|
|Short, Thomas - Zoetis|
Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2018
Publication Date: 4/24/2018
Citation: Walz, P.H., Riddell, K.P., Newcomer, B.W., Neill, J.D., Falkenberg, S.M., Cortese, V.S., Scruggs, D.W., Short, T.H. 2018. Comparison of reproductive protection against bovine viral diarrhea virus provided by multivalent viral vaccines containing inactivated fractions of bovine viral diarrhea virus 1 and 2. Vaccine. 36(26):3853-3860. https://doi.org/10.1016/j.vaccine.2018.04.005.
DOI: https://doi.org/10.1016/j.vaccine.2018.04.005 Interpretive Summary: Infection with bovine viral diarrhea virus (BVDV) contributes to a variety of economically important disease outcomes, but fetal infection with BVDV between 40-125 days of gestation, can lead to fetal infections result in persistently infected (PI) calves. Vaccination against BVDV is a common practice as a preventative measure to protect against fetal exposure to BVDV and subsequently fetal infection. While both modified live viral (MLV) and killed viral (KV) BVDV vaccines have been demonstrated to provide fetal protection, MLV vaccines have been shown to provide higher protection and longer durations of immunity. While superior protection afforded by MLV vaccines has been demonstrated, KV vaccines continue to be widely used by cattle producers because of potential safety concerns associated with MLV vaccination in close time proximity to breeding or during gestation. This study examined reproductive protection among commercially available KV vaccines against BVDV when challenge-exposed to persistently infected (PI) calves comprising all three BVDV genotypes present in North America. This study demonstrates the differences in reproductive protection conferred by three different KV vaccines. Of the three vaccines used in this study only one has been approved and licensed to prevent persistent infections associated with BVDV and it offered the greatest protection. This study demonstrates there are differences in efficacy associated with KV vaccines and it is important to understand these differences when choosing the appropriate vaccine to use in BVDV herd control programs.
Technical Abstract: The objective of this study was to compare reproductive protection in cattle against the impacts of bovine viral diarrhea virus (BVDV) provided by three different multivalent vaccines containing inactivated BVDV. Beef heifers and cows (n=122), seronegative and virus negative for BVDV, were randomly assigned to one of four groups. Groups A-C (n=34/group) received two pre-breeding doses of one of three commercially available multivalent vaccines containing inactivated fractions of BVDV 1 and BVDV 2 (A: CattleMaster® Gold FP®5 + Spriovac® L5: B:- Virashield™ 6 +L5 HB; C:- Triangle™ 10 HB). Group D (n=20) served as negative control and received two doses of saline prior to breeding. Animals were bred, and following pregnancy diagnosis, 110 cattle [Group A (n=31); Group B (n=32); Group C (n=31); Group D (n=16)] were subjected to a 28-day exposure to cattle persistently infected (PI) with BVDV (1a, 1b and 2a). Of the 110 pregnancies, 6 pregnancies resulted in fetal resorption without material available for BVDV testing. From the resultant 104 pregnancies, BVDV transplacental infections were demonstrated in 73 pregnancies. The PI rate was calculated at 13/30 (43%) for Group A cows, 27/29 (93%) for Group B cows, 18/30 (60%) for Group C cows, and 15/15 (100%) for Group D cows. Statistical differences were observed between groups with respect to post-vaccination antibody titers, presence and duration of viremia in pregnant cattle, and PI rates in offspring from BVDV-exposed cows. Group A vaccination resulted in significant protection against BVDV infection as compared to all other groups based upon outcome measurements, while Group B vaccination did not differ in protection against BVDV infection from control Group D. Ability of inactivated BVDV vaccines to provide protection against BVDV fetal infection varies significantly among commercially available products.