African Swine Fever: Prevention m is better than cure · Courtesy Sharon Brookes VLA 1 ml of blood...

“African Swine Fever: Prevention

is better than cure”

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CReSA and CReSA activities

Adapted from De la Torre, A and Arias , M. INIA-CISA

ASF: an African neglected disease

African Swine Fever

External membrane

NucleoidCapsid

Internal

membrane

Internal

membrane

Matrix

There is no vaccine available

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2019: ASFV outbreaks

• 1 million pigs sacrificed• 26 Provinces in China

• ASFV found in processed meat Vietnam is infected• Taiwan (ASFV positive carcases in the beach)

• China produced 639.82 million pigs in 2018

Map courtesy of Pig Progress

IMAGEN: Sánchez Cordón et al. 2018. Vet. J.

The current European scenario

The good news: ASFVs is transmitted by direct contact

HUMANS ARE NOT SUSCEPTIBLE TO ASF

ASF is not a human health concern, neither a social alarm

ASFV

But… humans are the main risk factor for ASFV

reintroduction

PREVENTION is the KEY!

ASFV

Do not underestimate the enemy!

Australia: ASFV in processd meet found at the airport

Same issue in Taiwan, South Coreaand Thailand

Taiwan: Carcasses found by the beach

ASFV

Complexity = success200 nm

Highly resistant in the environment

o days in fecesoYears in frozen carcasseso >140d in processed meatoUp to 18 months in blood (4˚C)!!!!

ASFV

Disinfectants:

2% sodium hydroxide, detergents and phenol substitutes, sodium or calcium hypochlorite (2-3% available chlorine), and iodine compounds

RB

C

RBC

V

VV

ASFV infected macrophage

ASFV-mediated hemadsorption ASFV hemagglutination

EVADING THE IMMUNE RESPONSE

Courtesy Sharon Brookes VLA

1 ml of blood might contain

100 million ASFV

particles!!!!!

ASFV

YX

• Early diagnosis and massive culling

Disease expansion!

- Endemic

poor countries No economic compensation

African swine fever Control

•There is no vaccine availableA

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Vaccines and ASFV

• Inactivated viruses (chemical or heat) don’t work or rendered controversial results.

•Proteins: partial protection or no protection.

•Long-term choice

•Attenuated viruses normally confer SOLID HOMOLOGOUS protection BUT safety issues

have hampered field implementation.

MECHANISMS OF PROTECTION

- Specific antibodies CAN INDUCE PARTIAL PROTECTION (passive transfer). Onisk et al,

1994.

-Specific CD8 T-cells CAN INDUCE PARTIAL PROTECTION (in vivo depletion). Oura et al,

2005.

Genetically attenuated viruses: a vaccine alternative for ASF?

ß-gusp72

L R

vF2

ß-gusp72

L R

vF1

ß-gusp72

L R

BA71TK

ß-gusp72

L R

BA71∆CD2CD2

Summary

1.Deletion of CD2 attenuates BA71 in vivo

2.BA71ΔCD2 protects in vivo in dose-dependent manner against lethalchallenges with:

a) BA71 homologous strain

b) E75 heterologous strain

3.BA71ΔCD2 induces CD8+ T-cells that specifically recognize homologousand heterologous ASFV strains in vitro

4.BA71ΔCD2 protects in vivo against Georgia07 heterologous lethalchallenge

Summary (II)BA71ΔCD2 protects in vivo against intranasal challenge

Full protection

BA71ΔCD2 protects in vivo against tick-bite infection (genotypes different than I and II)

Lack of CD2 difficult the tick transmission of BA71ΔCD2

BA71ΔCD2 can be grown in tissue culture cells (manufacturing)

BA71ΔCD2 protects in vivo

Further work is needed to optimize the vaccine:Safety DIVA

SFS-12-2019: A vaccine against African swine fever

• Developing safe and efficient DIVA vaccines against ASF

• Domestic pig and wild boar

• Collaborative project with third parties affected by ASFV• Stakeholders are essential• Participation of the Pharmaceutical industry is crucial

EU innovation project