Virally vectored ASFV antigens protect pigs from developing severe disease

Researchers at The Pirbright Institute have developed a vectored vaccine, which uses a non-harmful virus (adenovirus prime and modified vaccinia Ankara boost) to deliver eight strategically selected genes from the African swine fever 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. The study is published in Vaccines.

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 first 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 (DIVA). This is an important feature, as it allows vaccination programmes to be established without sacrificing the ability to trade.

“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” added Dr Netherton.

This research was funded by the Department for Environment, Food and Rural Affairs (Defra) and the Biotechnology and Biological Sciences Research Council (BBSRC), Part of UK Research and Innovation (UKRI).

Article: Goatley, L.C.; Reis, A.L.; Portugal, R.; Goldswain, H.; Shimmon, G.L.; Hargreaves, Z.; Ho, C.-S.; Montoya, M.; Sánchez-Cordón, P.J.; Taylor, G.; Dixon, L.K.; Netherton, C.L. (2020). A Pool of Eight Virally Vectored African Swine Fever Antigens Protect Pigs Against Fatal Disease. Vaccines, 8(2), 234, doi: 10.3390/vaccines8020234

[SOURCE: The Pirbright Institute]