Identification of African swine fever virus antigens for vaccine development

Scientists at The Pirbright Institute have identified African swine fever virus (ASFV) proteins that can induce cellular and humoral immune responses in pigs. Published in Frontiers in Immunology, the study shows that when some pigs were challenged with a virulent strain of ASFV after receiving a vaccine that included the identified proteins, the level of virus in the blood was reduced.

To determine which ASFV 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.

“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,” said Dr Chris Netherton, Head of the ASF Vaccinology Group at Pirbright.

There are various types of ASF vaccine being worked on, but relatively little is known about the virus and how the immune system responds to it, which hampers progression.

Vaccines made with inactivated viruses have not offered protection to domestic pigs, and although live attenuated vaccines show promise for protection, more testing is needed to ensure their safety. Pirbright researchers hope that these vector vaccines will provide an alternative.

Article: Netherton, C. L., Goatley, L. C.,Reis, A. L., Portugal, R., Nash, R. H., Morgan, S. B., Gault, L., Nieto, R., Norlin, V., Gallardo, C., Ho ChakSum, Sánchez-Cordón, P. J., Taylor, G., Dixon, L. K. (2019). Identification and Immunogenicity of African Swine Fever Virus Antigens. Frontiers in Immunology 10:1318, doi: 10.3389/fimmu.2019.01318

[SOURCE: The Pirbright Institute]