Galleau S. -HamersC. – Hudelet P. – Blanchet M. – Maurin-Bernaud L. –Duboeuf M. – Goutebroze S. / Merial S.A.S. – 69007 Lyon, France

1. SAFETY OF A BIVALENT BTV-4/BTV-8 INACTIVATED
VACCINE IN YOUNG CALVES
Galleau S.1 - Hamers C.1 – Hudelet P. 1 – Blanchet M.1 – Maurin-Bernaud L. 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-4/8 bivalent vaccine of the BTVPUR ALSAP® range administered to young calves.
Material & method
Vaccine 1st injection site (2 mL on D0)
18
To mimic any of the mono or bivalent combination of the BTVPUR ALSAP 2nd injection site (1 mL on D14)
Mean surface of local reaction (cm2)
range, an overformulated bivalent BTV-4/BTV-8 inactivated vaccine was 16
3rd injection site (1 mL on D28)
produced.
14
Study design
12
Twenty BTV sero-negative calves, aged between 23 and 30 days, were
randomly allocated to 2 groups of 10 animals each, on the basis of their 10
body weight:
8
Vaccinates: injected with the vaccine by SC route on D0 (double dose of
2 mL), D14 and D28 (repeated single dose of 1 mL). Each 6
vaccination was performed at separate injection sites.
4
Controls: injected with placebo (physiological saline) in the same
conditions as for vaccinates 2
Monitoring 0
0 10 20 30 40 50
- Individual clinical examination and recording of rectal temperature for 4
Day of observation
days following each injection.
- Monitoring of local reactions until D49 with subsequent necropsy and Figure 2: Evolution of average local reactions size in vaccinates after each injection
histological analysis of the injection sites.
- Recording of body weight gain.
Results Body weights
Clinical monitoring There was no impact of the vaccinations on the body weight gain.
Except very transient apathy and decrease of appetite in one calf
following the second injection, no treatment-related general reactions
were recorded. Box-and-Whisker Plot
The mean maximal temperature increase was +0.5°C, following the 103
second injection. Globally, the temperature increase remained very
Body weight (kg)
moderate and transient. 93
40.0 Vaccinates
*p=0.006, C ontrols
83
Student t test
Mean rectal temperature (°C)
p=0.487, p=0.744, Mann
73
Student t test Whitney W test
39.5
63
53
39.0
43
Vaccinates Controls Vaccinates Controls
38.5 D-1 D49
-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 D27 D28 D29 D30 D31 D32 Figure 3: Distribution of individual body weights measured in vaccinates
and controls on D-1 and D49
Figure 1: Evolution of mean rectal temperature following each injection
Local reactions
Only limited swelling reactions were observed at the injection sites, Table I. Relative Average Daily Weight Gain (% / day) per group
particularly after the 2nd and 3rd injections likely due to increased
inflammation in already primed animals. They had disappeared on D49 in Group Mean ± Sd Statistical comparison
all the calves except one (D28 injection site).
Vaccinates 1.3 ± 0.3
At histology, modification of very limited size, corresponding to a classical p=0.993
local subcutaneous foreign-body-like lesion (granulomatous inflammatory (Sudent t test)
Controls 1.3 ± 0.3
reaction), was recorded in only one third of the injection sites.
Conclusion
The administration of an overdose and repeated administration of one dose of the overformulated bivalent BTV-4/BTV-8
inactivated vaccine was demonstrated to be safe in one-month-old calves and does not impact the daily weight gain. The use of
commercial BTVPUR ALSAP can thus be considered safe in young cattle.
®BTVPUR ALSAP is a registered trademark of Merial.