Scientists in the United Kingdom have developed pigs that are completely resistant to classical swine fever (CSF) — a highly contagious and often fatal disease that continues to devastate pig farms around the world.
The breakthrough, led by researchers at the University of Edinburgh’s Roslin Institute, could offer a new way to protect livestock against one of the most destructive animal diseases.
In controlled trials, pigs carrying a single genetic alteration stayed healthy even after being exposed to the virus. Unedited animals, by contrast, developed the usual symptoms of the disease. Researchers reported that the edited pigs showed no negative effects on their health, growth, or fertility.
The study, published in the journal Trends in Biotechnology, demonstrates that precise gene editing can block infection by disabling a protein the virus depends on to multiply within pig cells.
“Our research highlights the growing potential of gene editing in livestock to improve animal health and support sustainable agriculture,” said Dr Simon Lillico, a research scientist at the Roslin Institute.
He explained that while earlier studies had shown the same effect in cell cultures, “translating that into living animals is a major step,” requiring specialized facilities to breed, monitor, and test the edited pigs safely.
The Edinburgh team focused on a gene that produces a protein known as DNAJC14, which pestiviruses — the virus family that includes CSF — need to reproduce. Changing just one amino acid in that protein was enough to stop the virus from processing its own proteins, halting its replication entirely.
Cells carrying the modified gene were also resistant to other pestiviruses that affect both pigs and cattle, suggesting the approach could help protect multiple species in the future.
Although classical swine fever has been eradicated in the UK, it remains a major concern in parts of Europe, Asia, and South America, where outbreaks cause enormous losses for farmers. Existing vaccines help reduce the spread, but the virus can persist in wild boar populations and move easily between herds.
“These are very promising results,” said Helen Crooke, Deputy Leader of Mammalian Virology at the UK’s Animal and Plant Health Agency (APHA), which partnered in the research.
“Cutting-edge tools like gene editing are showing the potential to play an important role in safeguarding animal health and welfare,” she said. “Classical swine fever is a devastating disease for livestock and farmers, as we saw with the outbreak in the UK 25 years ago. Hopefully this breakthrough can help bolster the resilience of the livestock sector.”
The work was carried out in collaboration with the University of Lubeck in Germany and supported by the animal genetics company Genus, along with funding from UK Research and Innovation (UKRI) and the Biotechnology and Biological Sciences Research Council (BBSRC).
Researchers say the discovery could one day form part of a broader strategy for controlling livestock diseases — used alongside vaccination, surveillance, and strong biosecurity — to protect herds and improve food security globally.
