Galleau S. -HamersC. – Hudelet P. –Montange C. – Duboeuf M. – Goutebroze S. / Merial S.A.S. – 69007 Lyon, France

1. SAFETY OF BIVALENT BTVPUR ALSAP® VACCINE IN
YOUNG LAMBS
Galleau S.1 - Hamers C.1 – Hudelet P. 1 – Montange C.1 – Duboeuf M.1 –
Goutebroze S.1
1 Merial S.A.S. – 69007 Lyon, France
Introduction
Bluetongue (BT) outbreaks have seriously affected the cattle and sheep industries in Europe. Since 2008, large-scale vaccination
programmes using inactivated vaccines have been conducted in Europe to control BTV infections, notably against BTV-8. Inclusion of young
animals in the vaccination programme is not only essential for the success of a BTV control strategy but also to ensure safe animal
movements. Consequently, safety of a vaccine to be used in young animals is of great importance for farmer’s acceptance of the vaccination
strategy.
The present study assessed the safety of an overdosed BTV-1/8 bivalent vaccine of the BTVPUR ALSAP range administered to young lambs.
Material & method
Study design 7
1st injection site (2 mL on D0)
2nd injection site (1 mL on D14)
Twenty BTV sero-negative lambs, aged between 29 and 36 days, were
Mean surface of local reaction (cm2)
randomly allocated to 2 groups of 10 animals each, on the basis of their 6 3rd injection site (1 mL on D29)
body weight:
Vaccinates: vaccinated with a bivalent BTV-1/BTV-8 inactivated and 5
overformulated vaccine by SC route on D0 (double dose of 2
mL), D14 and D29 (repeated single dose of 1 mL). Each 4
vaccination was performed at separate injection sites:
behind the right and left elbow (thoracic glabrous area) on 3
D0 and D14 respectively and in the right inguinal region on
D29.
2
Controls: injected with placebo (physiological saline) in the same
conditions as for vaccinates
1
Monitoring
- Individual clinical examination and recording of rectal temperature for 4 0
days following each injection. 0 10 20 30 40 50
- Monitoring of local reactions until D49 with subsequent necropsy and Day of observation
histological analysis of the injection sites.
Figure 2: Evolution of average local reactions size in vaccinates after each injection
- Recording of body weight gain.
Results
Clinical monitoring Body weights
No treatment-related general reactions were recorded.
There was no impact of the vaccinations on the body weight gain.
The mean maximal temperature increase was +0.9°C, following the
second injection. Globally, the temperature increase remained moderate
and transient. Box-and-Whisker Plot
p=0.150, *p=0.024, Mann *p=0.015, Mann
Student t test Whitney W test Whitney W test Vaccinates 33
Body weight (kg)
40.5
C ontrols
29
Mean rectal temperature (°C)
25
40.0
21
17
39.5
13
9
39.0 Vaccinates Controls Vaccinates Controls
-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
D-1 D0 D1 D2 D3 D4 D13 D14 D15 D16 D17 D18 D28 D29 D30 D31 D32 D33
D-1 D49
Figure 1: Evolution of mean rectal temperature following each injection
Figure 3: Distribution of individual body weights measured in vaccinates
Local reactions and controls on D-1 and D49
Only limited to moderate swelling reactions were observed at the
injection sites, particularly after the 2nd and 3rd injections likely due to
increased inflammation in already primed animals. They had disappeared Table I. Relative Average Daily Weight Gain (% / day) per group
or were of very limited size on D49. Longer persistence was observed at
the D29 injection sites due to the uncommon localization in the inguinal Group Mean ± Sd Statistical comparison
region.
At histology, the modification corresponded to a classical local foreign- Vaccinates 2.3 ± 0.2
p=0.785
body-like lesion of very limited size (encysted necrotic material (Sudent t test)
surrounding by fibro-inflammatory and macrophagic reaction) located in Controls 2.4 ± 0.3
the subcutaneous tissue.
Conclusion
The administration of an overdose and repeated administration of one dose of the overformulated bivalent BTV-1/BTV-8
vaccine was demonstrated to be safe in one-month-old lambs and does not impact the daily weight gain. The use of commercial
BTVPUR ALSAP can thus be considered safe in young sheep.
®BTVPUR ALSAP is a registered trademark of Merial.