In the absence of a vaccine, antiviral drugs could provide an alternative control method which would help limit clinical signs in pigs and lower ASF virus replication. This could reduce the spread of disease and help to contain outbreaks, ultimately reducing the number of pigs lost to this deadly viral infection.
In the absence of a vaccine, antiviral drugs could provide an alternative control method which would help limit clinical signs in pigs and lower ASF virus replication
The research, part funded by the Biotechnology and Biological Sciences Research Council (BBSRC) LINK programme, will test antiviral drugs that have already been screened in the laboratory by ViroVet and shown to reduce viral replication in cells in the absence of cellular toxicity. So far these antivirals have demonstrated at least a 90 percent reduction in viral replication. The most successful candidates will be further tested at Pirbright’s unique high containment facilities.
Scientists will assess whether the antiviral drugs are effective at preventing 14 different types of ASF virus from replicating in macrophages - immune cells which the virus infects in pigs. Further research will pinpoint how the antivirals work, and allow researchers to optimise the drugs to increase their ability to inhibit replication of a wide range of ASF virus strains. The most efficient candidates will then be trialled in pigs to establish the doses required and safety before testing effectiveness in reducing ASF virus replication and disease in pigs.
Antiviral drugs are already used in human medicine to treat diseases such as AIDS and hepatitis C for which no vaccines are available, and have served as an effective control method for a similar pig disease called classical swine fever. As commercial vaccines are several years away, the development of an effective antiviral treatment for ASF could aid the control of a disease which has continued to spread across Eastern Europe and China, recently appearing in Vietnam and Cambodia, decimating pig populations and threatening food security.
The disease represents an increasing risk to the UK pig industry as well, which is valued at around £1.2 billion. The current control of ASF is reliant on quarantine, movement restrictions and culling, which would all have high impacts on the livelihoods of British farmers and others involved in the pig industry if ASF were to enter the UK. Exports, currently valued at about £350 million, would also be halted.
Dr Linda Dixon, Head of the African Swine Fever Group at Pirbright, said: “The unique experience of ViroVet make them the ideal company to partner with on this project. The results from this study will help us understand more about how the virus infects pigs, and will help to inform our vaccine development research. Without a viable vaccine, ASF is incredibly difficult to control owing to its ability to be spread by wild boar and through the consumption of contaminated pork and other products by pigs. Having a tool which could lower the risk of further transmission once pigs have been infected would go a long way in preventing the rapid spread of this disease.”
Dr Nesya Goris, Chief Development Officer and co-founder of ViroVet added: “This joint research will help us select a potent antiviral drug that could stop transmission of ASF from infected animals and prevent spread to healthy pigs. We are extremely proud and honoured to partner with the expert scientists of The Pirbright Institute. The study will help advance the new concept of ASF containment using antiviral drugs.”