| | | |
Days post-2nd challenge Positive/total Viral titre ± standard deviation
|
|---|
|
Experiment
|
Group
|
Assay
|
+7 (91 pi)
|
+14 (98 pi)
|
|
1
|
C1 + B
|
Viral isolation
|
2/2
|
2/2
|
|
3.2 ± 0.6
|
2.0 ± 0.0
|
|
nRT-PCR
|
2/2
|
2/2
|
|
A + A
|
Viral isolation
|
0/4
|
0/4
|
|
nRT-PCR
|
4/4
|
1/4
|
|
A + B
|
Viral isolation
|
0/4
|
0/4
|
| | |
nRT-PCR
|
4/4
|
0/4
|
|
2
|
C2 + A
|
Viral isolation
|
3/3
|
2/3
|
|
3.4 ± 0.9
|
2.2 ± 0.1
|
|
nRT-PCR
|
3/3
|
3/3
|
|
B + B
|
Viral isolation
|
0/4
|
0/4
|
|
nRT-PCR
|
0/4*
|
0/4
|
|
B + A
|
Viral isolation
|
0/4
|
0/4
|
| | |
nRT-PCR
|
0/4*
|
0/4
|
- *Asterisks indicate statistical differences in the proportion of pigs found to be positive by RT-PCR in comparable groups of experiments 1 and 2 (i.e. homologous A + A versus homologous B + B).
