LSD symposium - W. Philips - Evaluation of the efficacy of live attenuated heterologous vaccines for the control of lumpy skin disease in cattle

1. EVALUATION OF THE EFFICACY OF LIVE
ATTENUATED HETEROLOGOUS VACCINES FOR
THE CONTROL OF LUMPY SKIN DISEASE IN
CATTLE
Wannes Philips
LSD Symposium: How science can support disease management and control, 14-16 March 2023, Rome, Italy

2. • Different options
• Live attenuated Vs inactivated vaccines
• Homologous Vs Heterologous vaccines
• Homologous vaccines (Live attenuated)
• LSDV-based vaccine
• Sufficient protection
• Adverse effects
• Neethling response
• Fever, milk yield,…
• Importance of Quality control
• Recombinant strains
• BTV detected
Vaccination to control LSDV

3. • Based on the cross protection between capripox viruses
• Two options
• Sheep pox based vaccines
• Goat Pox based vaccines
• Higher dose
• Field data suggest less protection for SPPV
• Limited adverse effects
• Cheap alternative for homologues vaccines
• Limited number of controlled animal trials
Heterologous vaccines (Live attenuated)

4. • Four sheep pox based vaccines (LAV1-4)
• LAV1: RM65 strain at 10X dose
• LAV2: RM65 strain at 10X dose
• LAV3: Bakirköy strain at 3X dose
• LAV4: Romanian strain at 5x Dose
• One goat pox based vaccine (LAV5)
• Gorgan at 10X dose
Vaccination-Challenge trial

5. • Clinical scoring
• Temperature
• Nodules
• General condition
• Food uptake
• Local reactions
• Humoral immune response: Immunoperoxidase monolayer assay (IPMA)
• Cellullar immune response: IFN-γ response following stimulation of heparinized blood
• Presence of viral DNA in blood via PCR
• Presence of viral DNA in organs via PCR
Follow-up during the trial

6. • SPPV LAVs
• No complete seroconversion at challenge
• If seroconverted: Low titers
• GTPV LAV
• Complete seroconversion at challenge
• Titer higher than SPPV LAVs
• Titers comparable to LSDV LAVs
Humoral response after vaccination
N
o
a
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0
2
4
6
#Animals
LAV1 LAV2 LAV3
LAV4 LAV5 LAV LSDV

7. • Vaccines classification based on
• Strength of response
• Duration
• SPPV LAVs
• Post-vaccination: classified as
weak or intermediate
• GTPV LAV
• Post-vaccination: classified as strong
Cellullar immune response after avccination
0 5 10 15 20
0
1
2
3
4
Days Post Vaccination
OD
LAV 1
0 5 10 15 20
0
1
2
3
4
Days Post Vaccination
OD
LAV 5

8. • SPPV LAVs
• Fever spike around 8dpc
• Fever persisted longer in LAV1
• Medium to severe local reaction
• GTPV LAV
• Fever spike around 7 dpc
• Limited swelling at site of inoculation
Temperature & Local reaction
0 5 10 15 20
38
39
40
41
Days post challenge
T
in
°C
LAV1
LAV2
LAV3
LAV4
LAV5
<2 cm 2-4 cm 4-7 cm >7 cm
0
1
2
3
4
5
Local swellings
#Animals
LAV1
LAV2
LAV3
LAV4
LAV5

9. • SPPV LAVs
• Development of nodules and/or clinical signs seen in animals in each group
• Comparable with control group (non-vaccinated)
• 6, 2, 4 and 7 animals with nodules
• GTPV LAVs
• Protection against clinical signs comparable with LSDV LAVs
Clinical signs
1
D
P
I
5
D
P
I
1
0
D
P
I
1
5
D
P
I
0
2
4
6
Clinical
score
LAV1
LAV2
LAV3
LAV4
LAV5
Controls

10. • SPPV LAVs
• Blood viremia in at least 3/7 animals for each vaccine
• Prolonged viremia in different animals
• GTPV LAVs
• No blood viremia seen after infection
Viremia
4
D
P
I
9
D
P
I
1
5
D
P
I
2
4
6
#Animals

11. • SPPV LAVs
• Viral DNA in all tested organs
• Very low ct-values at inoculation site and lesions
• GTPV LAVs
• Only two organs with viral DNA
• Very high CT-values (>40)
Viral DNA in organs
I
n
o
c
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l
a
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i
o
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s
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e
N
o
r
m
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0
2
4
6
Viral DNA in organs
#Animals
LAV1
LAV2
LAV3
LAV4
LAV5

12. • The SPPV based LAVs induced a weak humoral and cellular immune response after
vaccination.
• None of the SPPV based LAVs provided complete protection against a virulent LSDV
challenge (clinical signs, viremia)
• The GTPV LAV provided complete protection with strong humoral and cellular response
after vaccination comparable to homologous LSDV LAV vaccines.
• However, as only one GTPV LAV was examined, caution is needed when extrapolating this
to other GTPV LAVs. This results were in line with field data.
Conclusions

13. Thank you for your attention!
Special thanks to my colleagues
Andy Haegeman Ina Musch Maria Vastag Laurent Mostin
Ilse De Leeuw Sofie Diez Aicha El Kassri Willem Van Campe
Nick De Regge Gregory Scapardini Naoual Azeroual Arnaud Bouquiaux
Kris De Clercq Maryame Mejbar
Protecting people, animals, and the environment every day
This research was funded by the Bill & Melinda Gates Foundation project Nr OPP1126866, the GALVmed project Nr CAO-R34A0856
on lumpy skin disease and the Belgian Federal Public Service of Health, Food Chain Safety and Environment through the contract RT
15/3 (LUMPY SKIN 1).

14. Contact
Sciensano • Rue Juliette Wytsmanstraat 14 • 1050 Brussels • Belgium
T +32 2 642 51 11 • T Press +32 2 642 54 20 • info@sciensano.be • www.sciensano.be
Wannes Philips• wannes.philips@sciensano.be