Currently available vaccines important tools for managing PEDV-infected sow herds
Currently available vaccines can be important tools for managing sow herds endemically infected with porcine epidemic diarrhea virus (PEDV), indicates a study presented at the 2017 annual meeting of the American Association of Swine Veterinarians.1
Monitoring and maintaining levels of immunity sufficient to protect neonatal pigs is needed because there’s little possibility PEDV will be eradicated anytime soon, said Jordan Kraft, a veterinary student at Iowa State University.
Kraft and colleagues conducted a study to compare gilt responses to vaccination using two commercially available PEDV vaccines. Gilt immune response was measured by immunoglobulin levels, specifically IgA and IGg, and neutralizing antibody levels in serum, colostrum and milk samples.
PEDV antibody-positive commercial gilts were randomly assigned to one of five groups. One group received the commercial “Vaccine A” at 2 weeks pre-farrowing, and another group received the vaccine at 5 and 2 weeks pre-farrowing. The other commercial PEDV vaccine, “Vaccine B,” was also administered at 2 weeks pre-farrowing or at 5 and 2 weeks pre-farrowing. The fifth group received no vaccine and served as a control.
The investigators found that in gilts with prior exposure to PEDV, vaccination significantly (p < 0.05) increased IgG, IgA and neutralizing antibody levels based on samples of serum, colostrum and milk taken after farrowing. Gilts that received Vaccine B, a conditionally licensed Zoetis product, had higher IgG levels in serum and colostrum compared to the results with Vaccine A, Kraft reported.
Gilt serum antibody levels taken at 5 weeks pre-farrowing — before vaccination and measured as IgG and IgA by the fluorescent focus neutralization assay — were similar among the groups, which provides evidence that the differences found were due to vaccination, Kraft said.
1 Kraft J, et al. Serum and mammary secretion antibody responses in PEDV-exposed gilts following PEDV vaccination. In: Proceedings of the 48th Annual Meeting of the American Association of Swine Veterinarians (February 25-28, 2017). Page 50.