Animal experiment. Twenty-eight circovirus-free Yorkshire gilts (ca. 40 to 60
lb) were housed in the secure disease agent isolation facilities at the Plum Island
Animal Disease Center according to a protocol approved by the Institutional
Animal Care and Use Committee. In this experiment, the animals were divided
into five groups containing six animals per group (unless otherwise stated), and
each group was housed in a separate room: one group inoculated with 2 ml of 109
PFU Ad5-CI-pIFN-, one group inoculated with 2 ml of 1010 PFU Ad5-CIpIFN-
, one group inoculated with 2 ml of 109 PFU Ad5-CI-pIFN- and 1010
PFU Ad5-CI-pIFN-, and two control groups, one inoculated with 2 ml of 1010
PFU Ad5-Blue (four animals; two animals in this group were euthanized prior to
the start of the experiment because of health reasons) and one inoculated with
2 ml of phosphate-buffered saline (PBS). The animals were monitored clinically
for adverse effects from Ad5-CI-pIFN- and Ad5-CI-pIFN- administration,
including fever and lethargy. One day postinoculation two animals in each group
were slaughtered, and the remaining animals were challenged with 3.5 105
PFU of FMDV serotype A24, at two sites in the heel bulb of the right rear foot.
One day postchallenge (or 2 dpi) another two animals from each group were
slaughtered and the remainder of the pigs were monitored for clinical signs until
6 dpc (7 dpi) when they were also slaughtered. Lesion scores of the animals were
determined as described in Moraes et al. (37)