Efficacy of a commercial porcine epidemic diarrhea virus vaccine at reducing duration of viral shedding in gilts

Abstract

Objective: To evaluate if the use of a commercially available killed porcine epidemic diarrhea virus (PEDV) vaccine shortens the duration of PEDV shedding in replacement gilts. Materials and methods: Four treatment groups composed of 20 females were utilized for this study. Gilts in the CONTROL group had no previous exposure to PEDV, the nonvaccinated (NV) group had been previously exposed, and the PRE and POST groups received two doses of a commercial, killed PEDV vaccine either prior to or following a challenge with PEDV, respectively. Individual fecal samples were collected weekly and tested by realtime reverse transcriptionpolymerase chain reaction (rRTPCR) for virus detection. Results: Previous exposure to PEDV was found to shorten the time that virus can be detected in the feces compared to fecal samples of naïve animals (P < .001). Vaccination, either prior to or following the challenge, was not found to shorten the duration of PEDV shedding in feces. Implications: These results showed that vaccination of gilts, either prior to the challenge or afterwards, with a killed commerical PEDV vaccine did not shorten the period that virus was detectable in the feces by rRTPCR suggesting that viral shedding in feces was not influenced by administration of a killed commercial vaccine. While previous infection with virulent PEDV did not prevent reinfection, it did have a significant effect on the amount of time virus was detected following a subsequent exposure.