1) The study evaluated the impact of vaccination with Circovac on PCV2 shedding and tissue viral load in sows experimentally infected with PCV2. 2) The vaccinated group (VI) had lower virus shedding in samples collected and lower viral tissue loads compared to the unvaccinated (NVI) and control (C) groups. 3) Specifically, the VI group had fewer positive placentas and no positive fetuses, while the NVI and C groups did have some positive samples. This suggests vaccination reduced vertical transmission of the virus.

1. 4TH MERIAL FORUM
HAVE WE GOT PCVD &
SWINE INFLUENZA UNDER
CONTROL?

2. PCV2 impact and control on early
stage of gestation in sows
Giuseppe Sarli
4rd Merial Forum – Berlin – May 31st 2012

3. Target …..
• Results of a study conducted in 2010
EXPERIMENTAL INFECTION WITH PCV2
EXPOSED SEMEN OF CONVENTIONAL
CIRCOVAC® VACCINATED AND NON-
VACCINATED SOWS
• AASV Meeting 2012

4. Objectives of the study
To evaluate viremia, virus
shedding and viral load in
maternal serum, tissues
and fetuses in
a.6 PCV2 infected
Circovac© vaccinated gilts
b.6 PCV2 infected gilts
c.3 Control gilts

5. Trial 2009 ……..
PCV2 impact on early stage of
gestation in sows: experimental
results
• 6 PCV2 infected gilts
• 3 Control gilts

6. Trial 2009 results …..
• 4 out of the 6 infected sows developed
viremia
• Viremia was longer in the sow with the lowest anti-
PCV2 antibody titre
• In at least one organ of the six infected
sows PCV2 was detected
• The sow with the lowest anti-PCV2 antibody titre
showed the higher number of positive tissues and
fetuses

7. Groups for trial 2010
• 6 Circovac® + PCV2b
Hormonal estrus synchronization
infected gilts (VI)
– First vac.: 16 weeks
Artificial insemination with
– Second vac.: 20 weeks PCV2b spiked semen
= 4x1010 genome copy/ml
= 10 3.9 TCID50/ml
• 6 PCV2b infected gilts
(NVI)
Artificial insemination with
• 3 Controls (C) PCV2 negative semen

8. Experimental design
Control PCV2 PCV2 infected
infected + Circovac ®
Samples
analysis
D0 PCV2 PCV2  semen Cervix, nasal, rectal
swabs and blood
AI semen 10 ml
10 ml
103.9TCID50/ml sample every week
D29 Ultrasonography
Sow: uterus, lymph
D30 nodes placenta;
Euthanasia of empty sows
/D47 Fetus: lung,
amniotic fluid,
heart, liver
D52 RtPCR
Euthanasia of pregnant sows
/D56 Histology, IHC

9. Material and Methods
• Serology
• Real time PCR
– Swabs (vaginal, rectal, nasal)
– Blood
– Foetuses
– Gilts tissues
• Histology
– H&E
– Immunohistochemistry (for tissue ≥ 108 PCV2
genome copies/ml)

10. B: blood
Sampling S: swabs
: day of euthanasia

11. Pregnancy
• VI
– 3 out of 6 gilts were
pregnant
• NVI
– 3 out of 6 gilts were
pregnant
• C
– 2 out of 3 gilts were
pregnant

12. Serology: antibody titre

13. Real time PCR: serum, swabs and fetuses
ID Sera Fecal swabs Vaginal Nasal swabs
gilts swabs
108 ooo oo oooo
109 oo oo oo
110 o o oo
IV
112 o o o
114 oo ooo
115 o ooo o o
117 ooo oooooo ooooo ooooo
118 ooooo oooooo ooooo oooooo
119 oooooooo ooooooooo oooooo oooooooo
INV
123 oo ooooooo ooo ooo
126 oo oooo oooo ooo
127 o oooooo oo oooo
116 o oooo oooo ooo
CTR 120 oo oooooooo ooo oooo
122 oooooo oooooooo oooooooo ooooooooo

14. Real time PCR: serum, swabs and fetuses
n°positive samples n° sampling for each animal
N° positive N° positive N° positive
N° positive N° positive N° positive
Group ID N° viremia vaginal nasal amniotic
fecal swabs tissue fetus
swabs swabs fluid
108 0/8 2/9 4/9 3/9 12/20 0/3 0/3
Not Not
109 0/5 2/6 2/6 2/6 15/15
pregnant pregnant
Aborted Aborted
110 1/4 0/5 2/5 1/5 15/15
IV PCR- PCR-
Aborted Aborted
112 0/4 1/5 1/5 1/5 13/15
PCR- PCR-
114 0/7 0/8 3/8 2/8 23/42 0/15 0/15
115 1/8 1/9 1/9 3/9 5/30 0/9 0/9
total 2/36 6/42 13/42 12/42 83/137 0/27 0/27
Not Not
117 3/5 5/6 5/6 6/6 15/15
pregnant pregnant
Not Not
118 5/5 5/6 6/6 6/6 15/15
pregnant pregnant
INV 119 8/8 6/9 8/9 9/9 31/32 1/10 2/10*
123 2/7 3/8 3/8 7/8 42/46 0/16 1/16
Aborted Aborted
126 2/4 4/5 3/5 4/5 15/15
PCR- PCR-
127 1/8 2/9 4/9 6/9 36/41 0/14 0/14
total 21/37 25/43 29/43 38/43 153/164 1/40 3/40
Not Not
116 1/5 4/6 3/6 4/6 15/15
pregnant pregnant
CTR
120 1/8 3/9 4/9 8/9 26/26 0/7 0/7
122 6/8 8/9 9/9 9/9 28/32 1/10 0/10
total 8/21 15/24 16/24 20/24 69/73 1/17 0/17

15. IV INV CTR
Non-
Non-pregnant Pregnant
Pregnant sows Non-pregnant sows Pregnant sows pregnant
sows sows
sows
Sows ID 108 114 115 109 110 112 119 123 127 117 118 126 120 122 116
Number of
fetuses
3 15 9 0 0 0 10 16 14 0 0 0 7 10 0
Left tonsil + + - + + + + + + + + + + + +
Right tonsil - - - + + + + + + + + + + + +
Left uteriune
lymph node
- + - + + + + + + + + + + + +
Right uteriune
lymph node
+ - - + + - + + + + + + + + +
Left inguinal
lymph node
- - - + + + + + + + + + + + +
Right inguinal
lymph node
+ - - + + - + + + + + + + + +
Left ovary + + - + + + + + + + + + + + +
Right ovary + - - + + + + + + + + + + + +
Left salpinx + + - + + + + + + + + + + + +
Right salpinx - - - + + + + + + + + + + + +
Vagina + + + + + + + + + + + + + + +
Cervix - - + + + + + + + + + + + + +
Fetuses (pos/tot.) - - - / / / 1/10 - - / / / - 1/10 /
Amniotic fluid
- = 40%
- - / / / 2/10 1/16 - / / / = 76%
- - /
(pos/tot.)
= 77%
Placenta
(pos/tot.)
2/3 8/15 1/9 / / / 9/10 14/16 8/14 / / / 7/7 6/10 /
Left uterin tracts* + + + + + + + + + + + + + + +
Right uterin
tracts*
+ + + + + + + + + + + + + + +

16. Real time PCR: tissues
N° PCV2 positive N° positive tissue ≥ 108 PCV2 genome
Group Total tissue valued
tissues copies/ml
IV 127 83 6
INV 164 153 42
CTR 73 69 17

17. Histology
Animal (ear tag and group) Tissue PCV2 antigen localization
Follicular dendritic cell
117 INV Left tonsil
occasional histiocytic
Follicular dendritic cell
117 INV Right tonsil
occasional histiocytic
Follicular dendritic cell
118 INV Left tonsil
occasional histiocytic
Follicular dendritic cell
118 INV Right tonsil
occasional histiocytic
Left superficial inguinal lymph
118 INV Rare histiocytic
node
Right superficial inguinal
118 INV Rare histiocytic
lymph node

18. Summarizing the results …..
The vaccine was shown to have an active role in
reducing virus shedding and tissues viral load:
1.lower number of positive in vivo
collected samples in the VI group
compared to NVI and C

19. Summarizing the results …..
The vaccine was shown to have an active role in
reducing virus shedding and tissues viral load:
2.lower percentage of placentas and no
positive fetuses in VI gilts compared to
NVI and C groups

20. Summarizing the results …..
• Considering a similar antibody level at the
beginning of the experiment, their
quantitation should not take into
account the whole vaccine
effect.
• Role for mucosal immunity
triggered by vaccination ? Duodenum+jejunum+ileum

21. Acknowledgments
• Dept. Veterinary Medical • IZSLER
Science – Bologna
– Ostanello Fabio Infectious
diseases LS
– Dottori Michele Reggio
– Morandi Federico – Bonilauri Paolo Emilia
– Bianco Carlo – Cordioli Paolo
– Panarese Serena Pathology
Brescia
LS
– Lelli Davide
– Felice Viviana
– Ferrara Domenico
– Bacci Maria Laura • Merial
– Govoni Nadia Physiology
LS – Joisel Francois
– Galeati Giovanna Lyon
– Thais Vila Italy
– Giorgio Leotti

22. Thank you for your attention

23. Giuseppe Sarli
Department of Veterinary Medical Science
giuseppe.sarli@unibo.it
www.unibo.it