UK scientists have got a step closer to developing a vital vaccine for African Swine Fever (ASF). In a recent trial, 100% of pigs immunised with the new vaccine survived a lethal dose of ASF virus.
The research, carried out by scientists from The Pirbright Institute in the UK, was published in the peer reviewed journal Vaccines. According to a news release shared by the institute, the team developed a vectored vaccine, which uses a non-harmful virus (the vector) to deliver 8 strategically selected genes from the ASF virus (ASFv) genome into pig cells.
Once inside the cell, the genes produce viral proteins which primes the pig immune cells to respond to an ASF infection. All pigs that were immunised with the vaccine were protected from severe disease after challenge with an otherwise fatal strain of ASFv, although some clinical signs of disease did develop.
Vectored vaccine against ASF
In the news release, Dr Chris Netherton, head of Pirbright’s ASF vaccinology group, said: “It is very encouraging to see that the genes we have selected are able to protect pigs against ASF. Although the pigs showed clinical signs of infection after challenge with the virus, our study has shown for the 1st time that a vectored vaccine against ASF is a realistic possibility.”
This type of vaccine will also enable the differentiation of infected animals from those that have received a vaccine. According to the institute, that is an important feature, as it would allow vaccination programmes to be established without sacrificing the ability to trade.
The research paper stated that the data provide the basis for the further development of a subunit vaccine against ASF. Dr Netherton said, “Our next step will be to uncover the mechanisms behind how the proteins produced by the virus genes stimulate the immune system so we can refine and add to those included in the vaccine to improve effectiveness.”
Encouraging breakthrough against ASF
Christine Middlemiss, the UK’s chief veterinary officer, said in the news release: “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 African Swine Fever. While there has never been an outbreak of African Swine Fever in the UK, we are not complacent and already have robust measures in place to protect against animal disease outbreaks.”
Hopeful sounds with regard to ASF vaccine
The breakthrough is the 3rd time in a few months that positive news can be reported about the race to control ASF virus. In December 2019 researchers at the USDA’s Agricultural Research Service (ARS) announced they created a vaccine that could deliver sterile immunity against ASF.
In March 2020, Chinese researchers at Harbin Veterinary Research Institute communicated that they had developed a vaccine having deleted 7 gene segments from the virus to achieve that.
The original UK research paper in Vaccines was authored by Lynnette C. Goatley, Ana Luisa Reis, Raquel Portugal, Hannah Goldswain, Gareth L. Shimmon, Zoe Hargreaves, María Montoya, Pedro J. Sánchez-Cordón, Geraldine Taylor, Linda K. Dixon and Christopher L. Netherton, all attached to The Pirbright Insitute. Chak-Sum Ho is connected to the Gift of Hope Organ and Tissue Donor Network, Ithasca, IL, USA.