The French institute ANSES reports promising results in laboratory research aimed at developing a vaccine against African swine fever. The researchers succeeded in inactivating the Georgia 2007/1 virus strain. That is the virus strain currently circulating in the European Union.
While tracking the effects of heat treatment inactivation, the team accidentally discovered an attenuated strain derived from the Georgia strain. This strain caused only mild fever in infected animals, whereas infection with the Georgia strain is normally fatal in 100% of cases.
The team conducted a series of studies with this attenuated strain and confirmed that most pigs given this virus intramuscularly or oronasally showed only mild symptoms. Although the safety was not yet perfect, survival was much better than with infection with the original viral strain.
Another promising result is that infected pigs develop an immune response that allows them to resist infection with the virus without showing symptoms as early as two weeks after vaccination. The research results were published in December 2022 in the journal Viruses.
The ANSES scientists have continued to work on the attenuated strain, and can multiply it in cell lines produced in vitro. This is not necessary in cells taken from pigs, as was initially the case. This is important in order to be able to produce the vaccine on a large scale. Moreover, it appears that the virus strain produced in this way produces fewer disease symptoms than the original weakened strain, while the effectiveness is the same.
Studies are ongoing, particularly to ensure that the weakened strain cannot be passed from one animal to another or become virulent again. The scientists will also assess the vaccine’s ability to prevent animals that have been vaccinated and subsequently exposed to the African swine fever field virus from transmitting the virus again.
The vaccine developed by ANSES scientists has the advantage that it has not been developed through genetic engineering, which means that approval for use in the wild can be arranged relatively quickly. The use of the vaccine in wild boars in Western Europe is being considered. This is the animal species with the most infections and the presence of the virus in wild animals poses a risk to pig farms.
In order for these scientific discoveries to lead to effective industrial developments and ultimately to vaccine production, they must be transferable to the veterinary pharmaceutical industry. To this end, the laboratory filed a patent for the vaccine that was published last August. The Ouest Valorisation Technology Transfer Office supports ANSES in encouraging interested manufacturers to exploit this patent.
Copyright ©2023 AgriHolland B.V.