Fig. 5.
Protective efficacy in piglets of passive immunity from sow vaccination. Litters from VSVMT-SΔ19-vaccinated or mock-vaccinated sows were orally challenged with virulent PEDV SH2012 at 5 days of age. The mock-challenge controls, which were orally inoculated with PBS, were born from mock-vaccinated sows. Clinical significance scores were determined as described in the Materials and methods. (A) Piglet body weight changes (%). (B) Survival rate of piglets (%). (C) Piglet fecal score. (D) Virus shedding. PEDV viral RNA was extracted from rectal swabs of challenged or mock-challenged piglets and assessed by real-time RT-PCR. Values are the mean ± standard deviation. Statistical analyses among multiple groups of variance were conducted using a one-way ANOVA, with significant differences between means determined using Duncan's multiple range tests. *p < 0.05 and **p < 0.01 when the mean of the mock vaccination challenge group was compared with the mean of the mock challenge and vaccination challenge groups.