Date post: | 17-May-2015 |
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Health & Medicine |
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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!