| |
Nº of responding pigs; mean titre (log2 ) and standard deviation Range of titres (log2 ) for positive pigs
|
|---|
| |
Strain used in the viral neutralization test
|
|---|
| |
3262
|
3267
|
|---|
| |
Days post-inoculation
|
Days post-inoculation
|
|---|
|
Challenge group†
|
21
|
42
|
84
|
98
|
21
|
42
|
84
|
98
|
|
A + A
|
0/4
|
0/4
|
0/4
|
0/4
|
0/4
|
3/4*
|
4/4*
|
4/4*
|
|
(3262+3262)
|
-
|
-
|
-
|
-
|
-
|
1.7 ± 0.6a
|
2.0 ± 0.8a
|
4.25 ± 1.0b
|
| | | | | | |
(1–2)
|
(1–3)
|
(3–5)
|
|
A + B
|
0/4
|
0/4
|
0/4
|
0/4
|
0/4
|
2/4
|
2/4
|
4/4*
|
|
(3262+3267)
|
-
|
-
|
-
|
-
|
-
|
1.0 ± 0.0a
|
2.0 ± 0.0a
|
5.3 ± 0.5b
|
| | | | | | |
(1–1)
|
(2–2)
|
(5–6)
|
|
C1 + B
|
0/2
|
0/2
|
0/2
|
0/2
|
0/2
|
0/2
|
0/2
|
2/2*
|
|
(C+3267)
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
2.5 ± 0.5
|
| | | | | | | | |
(2–3)
|
|
B + B
|
0/4
|
2/4
|
4/4‡
|
4/4‡
|
4/4‡
|
4/4
|
4/4
|
4/4
|
|
(3267+3267)
|
0/4
|
1.0 ± 0.0
|
2.2 ± 1.5
|
2.8 ± 1.7
|
2.0 ± 0.8a
|
2.5 ± 1.0a
|
4.8 ± 1.0b
|
6.0 ± 0.8b¶
|
| |
-
|
(1–1)
|
(1–4)
|
(1–5)
|
(1–3)
|
(2–4)
|
(4–6)
|
(5–7)
|
|
B + A
|
0/3
|
0/3
|
3/3‡
|
3/3‡
|
1/3
|
3/3
|
3/3
|
3/3
|
|
(3267+3262)
| | |
2.0 ± 1.0
|
1.3 ± 0.6
|
1.0 ± 0.0
|
3.0 ± 1.0a
|
4.0 ± 1.0a
|
5.3 ± 0.6b
|
| |
-
|
-
|
(1–3)
|
(1–2)
|
(1–1)
|
(2–4)
|
(3–5)
|
(5–6)
|
|
C2 + A
|
0/3
|
0/3
|
0/3
|
0/3
|
0/3
|
0/3
|
0/3
|
0/3
|
|
(C+3262)
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
- † Chronological sequence of strains used for inoculation is shown in parentheses.
- * The asterisk show statistical differences (p < 0.05) for the proportion of responding pigs using one or the other PRRSV strain.
- Superscript letters indicate statistical differences (p < 0.05; ¶ p = 0.08) in the average titres between different days using a given strain.
- ‡ The symbol indicates statistically significant differences for the proportion of responding pigs for similar groups between experiments (i.e. homologous A + A vs. homologous B + B) using the same strain.
