Scientists at the Pirbright Institute in the UK appear to have taken a major step forward in developing an African swine fever vaccine (ASP). A recent study published in Vaccines magazine found that 100% of pigs immunized with the new vaccine survived an otherwise fatal dose of the ASP virus. The Pirbright team has developed a vaccine that uses a non-harmful virus as a vector to deliver eight selected genes from the ASP pathogen to pig cells, the institute said. There they produce viral proteins that cause the pig’s immune system to respond to an ASP infection. All pigs immunized in this way developed sufficient protection to survive the usually fatal ASP infection, even if the disease showed clinical symptoms. Another success was, according to the researchers, that this method makes it possible to differentiate whether pigs have been vaccinated or actually have ASP. This is important so that vaccination programs can be carried out without losing marketability. The next step will be to uncover the mechanisms by which the proteins produced by the virus genes stimulate the immune system so that the effectiveness can be improved.
Worldwide search for ASP vaccine
In other countries, scientists had already reported intermediate successes in the ASP vaccine search. In December 2019, researchers at the U.S. Department of Agriculture’s Agricultural Research Service (ARS) announced that they had developed a genetically engineered vaccine that offered aseptic immunity to ASP after low and high-dose injections. In March 2020, the Chinese Harbin Veterinary Research Institute announced that a live vaccine had been developed by means of gene deletion, in which seven gene fragments had been deleted from the ASP virus and which offered reliable protection against the animal disease
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