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Table 2 Clinical score, lung lesion score and re-isolation of the challenge strain after immunization of pigs with different vaccines, followed by heterologous intranasal challenge with A. pleuropneumoniae

From: Type IV fimbrial subunit protein ApfA contributes to protection against porcine pleuropneumonia

Vaccine1

Number of pigs2

Clinical score3

Body temperature (°C)4

Lung lesion score5

Re-isolation of the challenge strain (%)6

Surviving pigs (%)

rApfA

12

1.7 ± 0.77

40.3 ± 0.57

1.3 ± 0.77

587

100

rApxIVA

3

2.6 ± 0.5

40.8 ± 0.4

1.8 ± 0.5

100

100

rTbpB

3

2.7 ± 0.5

40.9 ± 0.5

1.9 ± 0.7

100

100

rApxIA+rApxIIA+rApxIIIA

3

1.9 ± 0.7

40.5 ± 0.4

1.5 ± 0.6

100

100

rApxIA+rApxIIA+rApxIIIA+rApxIVA+rTbpB

7

1.2 ± 0.57

39.9 ± 0.47

1.0 ± 0.67

86

100

rApfA+rApxIA+rApxIIA+rApxIIIA+rApxIVA+rTbpB

7

0.3 ± 0.57,8

39.6 ± 0.57

0.3 ± 0.57,8

297

100

Control (PBS in oil adjuvant)

7

3.2 ± 0.7

41.2 ± 0.4

2.3 ± 0.7

100

57

Non-treated

2

0

39.1 ± 0.4

0

0

100

  1. 1Pigs were immunized with two doses of the indicated vaccines at two week intervals and challenged intranasally two weeks later with A. pleuropneumoniae serotype 9 strain (2 × 108CFU).
  2. 2Two independent immunization and challenge experiments were performed. Total number of pigs per vaccine group is given.
  3. 3Following the challenge, pigs were examined for clinical signs of pleuropneumonia and scored every day for seven days using a 0 to 4 scale. Mean value for each vaccination group calculated from two independent challenge experiments ± standard deviation is given.
  4. 4Following the challenge, body temperature was taken daily for seven days. Mean value for each vaccination group calculated from two independent challenge experiments ± standard deviation is given.
  5. 5Upon death, or immediately upon sacrifice on day seven, all animals underwent necropsy and macroscopic inspection of lungs. The observed lung lesions were scored using a 0 to 3 scale and mean value for each group calculated from two independent challenge experiments ± standard deviation is given.
  6. 6Percentages of pigs in each vaccination group from which the challenge strain of A. pleuropneumoniae was re-isolated.
  7. 7Statistically significant difference (P < 0.02) between the vaccine immunized group and the control group, each comprising at least 7 animals.
  8. 8Statistically significant difference (P < 0.02) between the combined hexa-antigen vaccine (rApfA, rApxIA to IVA and rTbpB) immunized group and the penta-antigen vaccine (rApxIA to IVA and rTbpB) immunized group.