CIRCOVAC® vaccination efficacy on piglets

Mathias RitzmannB. Heissenberger, A. Ladinig, H. Söllner, C. Püschel, C. Lang

Clinic for Swine University of Veterinary Medicine Vienna

University of Veterinary Medicine Vienna

Clinic for Swine

Objective

Efficacy of Circovac® piglet vaccination

An Austrian field study

Farm Austrian farrow-to-finish farm

Farm Austrian farrow-to-finish farm

250 sows

Farm Austrian farrow-to-finish farm

250 sows

4 week batch interval

All-in / all-out

Farm history

Diagnosis of PMWS

Increasing percentage of wasting animals

Increasing mortality rate

PCV2 infection confirmed by

Histopathology

Detection of PCV2 in lymph nodes by in situ hybridisation (ISH)

Quantification of PCV2 in lung samples

Study procedures

1105 piglets from 3 consecutive batches

Piglets randomly allocated to Vaccination group and to Control group

Study procedures

1105 piglets from 3 consecutive batches

Piglets randomly allocated to Vaccination group and to Control group

Vaccination of 3 week old piglets with Circovac® 0.5 ml i.m. as One-Shot

Application of Placebo to piglets of Control group

Vaccinated and control group animals stayed intermingled

Blood sampling: 20% of all piglets

Monitoring from birth until end of fattening

Study schedule

Birth21st week

Vaccination/Placebo

Weighing

Weaning

Weighing

End of fattening

3rd week 13th week

Weighing

End of nursery

Weighing

Mid of fattening

28th

week

Blood samples weekly

Blood samples bi-weekly

Results: Significant increase of average daily weight gain

+ 64.83

13th – 21st week = main viremia period

Average daily weight gain (g/day)

609.61 651.040

100

200

300

400

500

600

700

13th - 28th week (Overall fattening period)

g/day

Control group Vaccinated group

+ 41.43

p<0.0001

Average daily weight gain (g/day)

519.97 584.800

100

200

300

400

500

600

700

13th - 21st week (Early fattening period)

g/day

Control group Vaccinated group

p<0.0001

+ 64.83

Results: Significant reduction of wasting animals

p=0.0044

- 5.15

p<0.05

Wasting animals in the 21st

week of life

19.87 14.720

5

10

15

20

21st week

%

Control group Vaccinated group

p<0.05

Results: Significant reduction of mortality rate

- 7.40

p<0.0001p<0.0001

13th – 21st week = main viremia period

Mortality rate

8.55 2.530

2

4

6

8

10

13th - 21st week (Early fattening period)

%

Control group Vaccinated group

- 6.02

p<0.0001

Mortality rate

11.41 4.010

24

68

10

1214

13th - 28th week (Overall fattening period)

%

Control group Vaccinated group

p<0.0001

- 7.40

Results:Laboratory testing

Efficacy of vaccination over timeInvestigation of animals from batch 1 and 3

Results:Laboratory testing

Quantity of PCV2 in serum: qPCR Copies/ml serum in median LOG values

Seroconversion: Ingezim Circovirus IgG/IgM Pos/Neg decision

Results: Reduction of viremia and virus shedding

Median LOG values Batch 1

0

1

2

3

4

5

6

7

8

6 10 12 14 16 18 20 22 24 26 28

age (weeks)

coip

es/m

l LO

G

Vaccinated group Control group

Median LOG values Batch 3

0

1

2

3

4

5

6

7

8

6 10 12 14 16 18 20 22 24 26 28

age (weeks)

coip

es/m

l LO

G

Vaccinated group Control group

Conclusion – Viremia

qPCR dataEfficient reduction of virus shedding by vaccination

of piglets with 0.5 ml Circovac® i.m.

Efficient reduction of virus shedding over time from batch 1 to batch 3, this means reduction of viral pressure with ongoing vaccination program

Results: Serology

Batch 3 Vaccinated group

0

20

40

60

80

100

6 10 12 14 16 18 20 22 24 26 28

age (weeks)

%

IgG IgM

Batch 3 Control group

0

20

40

60

80

100

6 10 12 14 16 18 20 22 24 26 28

age (weeks)

%

IgG IgM

Batch 1 Vaccinated group

0

20

40

60

80

100

6 10 12 14 16 18 20 22 24 26 28

age (weeks)

%

IgG IgM

Batch 1 Control group

0

20

40

60

80

100

6 10 12 14 16 18 20 22 24 26 28

age (weeks)

%

IgG IgM

Conclusion – Serology

After infection, vaccinated animals had a lower incidence for IgM antibodies compared to thecontrol group animals

Vaccinated animals positive for IgM antibodies in the 6th week of life immune response to vaccination

Serology on its own is not sufficient for evaluating vaccine efficacy just in combination with qPCR and clinical data (ADWG, mortality rate…)

Summary

Main viremia occurred first half of fattening

Significant improvement of average daily

weight gain

Significant reduction of wasting animals

Significant reduction of mortality rate

Thank you for your attention!