PEDV is a highly pathogenic and transmissible virus in swine, first detected in the US in May 2013, and it has caused tremendous losses to the swine industry, according to Ron Batman of Newport Laboratories Inc.

In a paper in BMC Veterinary Research, he and co-authors there, at South Dakota State University, Kansas State University and Egypt's National Research Center, explains that, due to the difficulty in isolating and growing this virus in cell culture, few vaccine studies using cell culture propagated PEDV have been performed on US strains in pigs.

The objective of this study was to evaluate the humoral immune response to the selected inactivated PEDV vaccine candidate in a dose-titration manner.

PEDV was isolated from a pig with diarrhoea and complete genome sequencing found more than 99 per cent nucleotide identity to other US PEDV.

Inactivated adjuvanted monovalent vaccines were administered intramuscularly to five-week-old pigs in a dose titration experimental design, ranging from 6.0 to 8.0 log₁₀ tissue culture infective dose (TCID₅₀ per mL), to evaluate immunogenicity using a fluorescent foci neutralisation assay (FFN), fluorescent microsphere immunoassay (FMIA), and enzyme-linked immunosorbent assay (ELISA) on sera.

Pigs vaccinated with 8.0 log₁₀ TCID₅₀ per mL inactivated virus showed significantly higher FFN titres as well as FMIA and ELISA values than 6.0 log₁₀ TCID₅₀ per mL vaccinates and the negative controls.

Batman and co-authors conclude their results demonstrate the immunogenicity of a PEDV-inactivated viral vaccine with a US strain via dose-titration.

They add that a future vaccination-challenge study would illustrate the efficacy of an inactivated vaccine and help evaluate protective FFN titres and ELISA and FMIA responses.

Reference

Collin E.A., S. Anbalagan, F. Okda, R. Batman, E. Nelson and B.M. Hause. 2015. An inactivated vaccine made from a US field isolate of porcine epidemic disease virus is immunogenic in pigs as demonstrated by a dose-titration. BMC Veterinary Research. 11:62. doi:10.1186/s12917-015-0357-1

Further Reading

You can view the full report (as a provisional PDF) by clicking here.

April 2015