PROGRESS HAS been made towards developing a vaccine for African Swine Fever after UK scientists identified proteins that can trigger an immune response in pigs.

Scientists at The Pirbright Institute found that when some pigs were challenged with a virulent strain of ASF after receiving a vaccine that included the identified proteins, the level of virus in the blood was reduced. It has been suggested that this method of vaccination could provide effective protection to pigs following further research.

Head of the ASF Vaccinology Group at Pirbright, Dr Chris Netherton said: “ASFV has more than 150 proteins; understanding which of these triggers an immune response is difficult but crucial for creating this kind of vaccine. Now we have identified proteins that activate pig immune cells, we can work on optimising the vaccine components to ensure pigs are protected against virulent ASF strains."

To determine which ASF proteins should be used in the vaccine, the team screened proteins to find those that activated immune cells in pigs, which had previously been infected by a weakened form of ASFV. The 18 proteins that generated the strongest immune cell response were then transferred into viral vectors; viruses which deliver the ASF proteins to pig cells, but are not harmful to pigs.

The development of a safe and effective vaccine against ASF is vital – the disease has caused devastation in Asia resulting in the culling of over 1.1m pigs in China and nearly 2.5m pigs in Vietnam alone. Culling, quarantine and strict biosecurity measures are currently the only defences farmers can use to prevent its spread. Europe’s largest pig producer Denmark is currently in the progress of building a 43-mile border fence to keep wild boar from bringing the disease into the country and the whole of Europe is on high alert to minimise the risk of the virus getting into the commercial pig herd.

UK Chief Veterinary Officer, Christine Middlemiss, commented: “I welcome this research by The Pirbright Institute which demonstrates the UK’s world-leading role in developing the science and tools needed to tackle devastating animal diseases such as African swine fever. While this is encouraging progress, we continue to work closely with the UK pig sector to raise awareness of the risks and advise on maintaining high biosecurity standards, including minimising the risk of the virus infecting commercial pigs,” she concluded.

ASF cause fevers, loss of appetite, vomiting and bloody diarrhoea in all pigs and wild boar. The disease is often deadly, with some strains approaching case fatality rates of 100%. The virus does not cause disease in humans, but it does pose a significant threat to food security and has a substantial impact on the economy, especially on trade and farming.