Graduate Student University Of Kentucky , Gluck Equine Research Center Lexington, KY, United States
Abstract:
Background: Equine rotavirus B (ERVB) is an emerging pathogen that causes severe diarrhea in foals. Currently, there are no vaccines to prevent ERVB infection in horses. Hypothesis/
Objectives: This study is to develop a baculovirus-based VP8 vaccine that protects foals against ERVB infection. Animals: 15 healthy horses and 12 healthy pregnant mares were employed in this study.
Methods: In Study 1, horses were divided into two groups (10 vaccinated,5 controls), with each group receiving two doses of vaccine or sham control respectively at 3 weeks apart. Serum samples were collected from these horses before and after immunization, which were assayed for VP8 antibody responses. Study 2 divided pregnant mares into two groups (6 vaccinated, 6 sham vaccinated), who were vaccinated during their 8th, 9th, and 10th month of gestation. On day 1 of life foals were orally challenged with ERVB. Colostrum and serial blood samples from foals were collected for measuring VP8 antibody titers in ELISA. Collected fecal samples were analyzed by RT-qPCR to determine viral shedding.
Results: All vaccinated horses remained clinically normal, with no clinically relevant adverse reactions observed. In study 1, a robust VP8 antibody response was detected. In study 2, following viral challenge, 2 out of 6 foals from the vaccination group were completely protected, with the other 4 foals shedding lower quantities of the virus compared to infected foals from the sham vaccination group. Conclusions and Clinical Importance: The baculovirus-based VP8 vaccine is safe, immunogenic, and effective to protect foals from ERVB infection.
