The response of pregnant gilts previously given an inactivated preparation of porcine parvovirus (PPV) to challenge infection with a fully virulent PPV.

Eight 40-day pregnant gilts, previously treated with an adjuvanted-inactivated viral preparation (AIVP) obtained with a field strain of porcine parvovirus (PPV) together with 4 pregnant untreated controls, were subjected to challenge infection with a virulent strain of PPV at the 40th day of gestation. After challenge, all controls became febrile for 2 to 8 days, whereas only one gilt among those which had been treated with the AIVP experienced fever which lasted 4 days. Virus was consistently recovered from fecal swabs obtained from the controls and only sporadically from feces of AIVP-treated gilts. When the gilts were killed 53 days after challenge infection, no macroscopic lesions were found in any of the gilts in either groups, but fetal death was observed in the two groups of animals. However, the rate of dead fetuses was much higher among the control (70.5%) than among those from the AIVP-treated gilts (10.1%). Virus was recovered from 23 of the 24 dead fetuses in the control group and only from 3 among the 8 dead fetuses which were reported for the AIVP-treated gilts.