Information Page: African Swine Fever

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Animal Health Industry Declaration

ASFdeclarationwebAnimalhealthEurope members have joined together with HealthforAnimals, the global animal medicines association, to publish a Declaration on African Swine Fever. This declaration recognises that ASF is an unprecedented crisis that threatens animal welfare along with food security and the livelihoods of people around the globe.

Our Declaration outlines the challenges and a vision for better control while we work towards a vaccine. This includes increasing biosecurity, timely outbreak reporting, leveraging trade measures like compartmentalization, and preparing regulatory systems for vaccine candidates.

Our Members have made clear commitments in this Declaration towards improving ASF management, collaborating with governments, and supporting biosecurity adoption. The disease cannot be stopped by just one group or sector though, which is why the Declaration also offers clear actions policymakers can undertake to lessen the crisis and spur vaccine development.

- Increased Research Support         

- Public Private Partnerships

- Timely Data Sharing

- Outbreak Preparedness

- Greater Biosecurity Support

- Vaccine Bank Commitments

- Fast-Track Approvals

 


We urge all organisations to support this declaration and work towards a world free of African swine fever.
 

European Union Reference Lab for ASF – Vaccine Research

CISA-INIA (Centre for Animal Health Research at the Spanish National Institute for Agriculture) is the designated EU Reference Laboratory for ASF (EURL-ASF) and €161.5 million were dedicated to eradication and control (2014-2019). In October 2019 the European Commission financed a research project – VACDIVA - with 10 million euros to support research work for a safe DIVA vaccine for the control and eradication of African swine fever.

We caught up with project coordinator, Prof. Jose Manuel Sanchez-Vizcaino from Madrid’s Complutense University to find out how the project is going.

About the project:
VACDIVA counts the participation and experience of the EU reference laboratory for ASF (EURL), the OIE and FAO reference laboratories, six national reference laboratories in Europe, four prestigious ASF research centres, as well as industry and farmer association backing, along with other research groups with much experience in ASF from Russia, China and Africa.

Main challenges:
Overall, vaccine development has been hindered by the virus’ genetic complexity, high virulence of some ASF strains, gaps in knowledge concerning the viral proteins involved in real protection, the lack of development of neutralizing antibodies, and some more technical difficulties such as the lack of stable cell lines. Previous attempts to vaccinate animals using inactivated vaccines had failed to produce immunity.

Fortunately, thanks to a very dedicated consortium of researchers, animal trial work was not delayed during the height of the COVID-19 lockdowns. Ongoing tests in live animals were permitted allowing the project to advance

Progress so far:
One year on from the project’s start (October 2019), Jose happily reports that they have now found the first promising vaccine against ASF virus in wild boar by oral administration (link to paper). This past year a lot of progress was made in the molecular biology, in identifying the genes linked to virulence rather than immune response. This facilitated the identification of attenuated vaccine candidates either from naturally attenuated ASF virus or their production by gene deletion. The VACDIVA project is now working on 3 prototypes, running with promising results so far.

The project first concentrated on a wild boar vaccine as the majority of European countries impacted report wild boar as the main host affected by the disease, but Jose confirms that the prototypes are in testing for both wild boar and domestic pigs. Good news for farmers, is that the project’s prototypes are DIVA vaccines, meaning it will be possible to differentiate infected from vaccinated animals, hopefully avoiding any trade issues following vaccination programmes in the future.

What next?:
A lot of work still lies ahead with the vaccine safety testing, as the vaccine needs to be tested for safety, for food safety and also for environmental risks. Safety data obtained very recently in the wild boar trial has been very promising. Stability testing will also be part of this process and these tests all take a lot of time, but Jose remains confident that by the end of the project’s duration (until October 2023) a vaccine will be ready for market authorisation.

VACDIVA will also develop cost-benefit and effective surveillance and control strategies for vaccination, to help advise the EU and other international parties on the best conditions for vaccination. What remains in question however, is whether a vaccine developed here in Europe will work for the strains circulating in other countries around the world due to the great genetic variability of the ASF virus.These studies are also included in the VACDIVA project goals.

OIE Reference Lab for ASF- Vaccine Research

The World Organisation for Animal Health (OIE) works with a network of reference labs on the control and management of ASF, including: CSIRO Australian Centre for Disease Preparedness; Onderstepoort Veterinary Institute (South Africa); Centro de Vigilancia Sanitaria Veterinaria (VISAVET, Spain); and The Pirbright Institute (UK).

We caught up with Dr Chris Netherton, Group Leader of African Swine Fever Vaccinology at The Pirbright Institute to catch up on vaccine research progress.

Status of research work:
Chris talked about the two approaches currently being taken at The Pirbright Institute to develop vaccines against ASF.
The first approach is to develop live attenuated virus vaccines, these are essentially weakened forms of the virus. We are using laboratory techniques to identify ASF virus (ASFV) genes that modify host immune responses, these are then targeted for deletion from the ASFV genome. Dr Linda Dixon’s group at Pirbright has identified a number of these genes and has shown that the targeted gene deletions weaken the virus. The immune response generated against these weakened strains protect pigs against a subsequent encounter with a normally lethal strain of the virus. Work continues at Pirbright to characterise these gene deleted viruses and further improve their safety profiles. Researchers in other institutions are following similar approaches, with success being reported by a group at Plum Island Animal Disease Center in the US and at the Harbin Institute of Technology in China. The Harbin vaccine is currently being trialed in the field in China and no problems have been reported to date.

The second approach is a subunit vaccine. This involves using a harmless virus to deliver parts of the ASFV genome which will produce virus proteins when they enter pig cells, triggering an immune response. This has a couple of advantages over live attenuated viruses; they should be very safe as they are not based on infectious ASFV and they should also be able to differentiate infected from vaccinated animals (DIVA). However, it is more challenging to engineer this type of vaccine to generate an efficient immune response that can fully protect pigs. We recently reported 100% protection from fatal disease with a subunit vaccine, however the animals still got sick after they were infected with ASFV, which we are working to improve.

Any challenges due to COVID-19 or other?:
COVID-19 caused some limited disruption during the full lockdown in the UK, but Chris pointed out that the animal trials that underpin our vaccine research were not affected. Some members of staff also helped with the UK diagnostic effort. The current focus on COVID-19 vaccine research may eventually provide opportunities for ASF vaccine research too. For example: the University of Oxford’s ChAdOx1 vaccine uses a similar technology to our subunit vaccine.

Any estimation on timing and potential to use around the world?:
The ‘when?’ is a very important question, but as ever this is difficult to answer. A subunit vaccine is definitely a number of years away. Chris says that if the Harbin vaccine trials go well, then we could see a wider application within a shorter timescale.

The genetic sequence of the viruses causing outbreaks in Europe and Asia are very similar and therefore a vaccine that works against European strains of ASFV should also work in Asia and vice versa. It is a different story in sub-Saharan Africa though. There have been outbreaks of ASF caused by a virus that is similar to the Eurasian strain, but there are a number of other genetically distinct viruses across the continent. Some cross-protection has been observed in the past, so it is possible a European vaccine would work more widely, but it would need to be tested.

Eradicating ASF from wild boar will need a vaccine that can be delivered using baits. It is likely that a live attenuated virus vaccine can be administered this way, but again this will need further testing.

Situation in Europe

ASF was introduced into the EU in 2014 and has spread through eastern Europe, jumping to western Europe in 2018 when it was reported in wild boar in Belgium.

Cases have been notified to the EU Animal Disease Notification System in 13 countries (LT, PL, LV, ET, RO, BG, SK, RS, GR, CZ*, HU*, BE*, DE*). ASF is also present in many countries on the eastern border of the EU.
* Cases reported in wild boar only

The EU has developed a harmonised strategy to tackle the disease in affected countries and to prevent the occurrence in disease-free territories in the EU. 

Updates from Poland:

    •  ASF has been present in Poland since 2014 and over 300 farms have reported infections since then.

    • Updates can be found on the website of the Polish Veterinary Inspectorate

    • Authorities have taken the following actions:
    • Sharing ASF information for breeders and entrepreneurs 
    • Providing compensation from the state budget, an extra financial support for those who discontinue pig farmin
    • Promoting biosecurity measures, providing extra money for biosecurity equipment, offering trainings and instructional videos
    • Partnerships with hunters, providing compensation for shooting wild boars
    • Offering compensation for informing the police of dead boar carcasses

Updates from Germany:

  • ASF was first reported in wild boar in Germany in September 2020.

  • German authorities have increased their efforts to contain the virus in the wild boar population, including the deployment of specially trained sniffer dogs. 

  • Regular situation updates can be found on the Friedrich-Loeffler Institute website, along with interactive maps.

Updates from Belgium:

    • In September 2018 the first cases of African swine fever were reported in wild boar in the south of Belgium.
    • Strict measures were implemented for the whole country to prevent contamination of domestic swine.
    • The last positive case confirmed on a fresh carcass dates from the 11th of August 2019.
    • There have been no reported outbreaks in domestic swine.
    • Further information can be found on website of the Belgian Federal Agency for the Safety of the Food Chain