21 May 2020
Scientists at the institute say a vital vaccine for a major killer of pigs is significant step closer, after new study showed immunisation in 100% of test pigs.
Paul Imrie
Job Title
Image © The Pirbright Institute
A vaccine against a deadly disease with potential to kill a quarter of the world’s pigs is a step closer after The Pirbright Institute reported a world-first breakthrough.
According to the World Organisation for Animal Health (OIE), lack of a commercially available African swine fever (ASF) vaccine is putting a significant proportion of the planet’s pigs at risk – more than seven million died as a result of ASF in 2019.
A team of scientists at Pirbright has now made a breakthrough, reporting in a study in Vaccines that 100% of pigs immunised with a new vaccine were protected from a lethal dose of ASF virus (ASFV).
The team created a vectored vaccine by inserting eight strategically selected ASFV genes into a non-harmful virus vector.
The vector primed the pig immune system to respond to ASF infection. Although clinical signs did develop, the combination of eight virus genes protected pigs from severe disease after challenge with an otherwise fatal strain of ASFV.
It is the first time a vectored vaccine has shown a protective effect against ASF – and while further work is needed, if successful a vaccine would enable the differentiation of infected animals (DIVA) from those that have received a vaccine – allowing a vaccination programme to be developed that did not sacrifice ability to trade.
ASF is spreading across eastern Europe and Asia, and stringent biosecurity measures and culling of susceptible animals are the only current methods to bring it under control.
Chris Netherton, head of Pirbright’s ASF vaccinology group, said: “Demonstrating that our vaccine has the potential to fully protect pigs against ASF is a huge step in our vaccine development programme. We have already begun work to refine the genes included in the vaccine to improve its effectiveness and provide more protection.”
UK CVO Christine Middlemiss said: “This is a very encouraging breakthrough, and it means we are one step closer to safeguarding the health of our pigs and the wider industry’s role in global food supply from ASF.
“While there has never been an outbreak of ASF in the UK, we are not complacent and already have robust measures in place to protect against animal disease outbreaks.”
This research was funded by Defra, and the Biotechnology and Biological Sciences Research Council – part of UK Research and Innovation.
