New Hope has found strains of the virus missing both the MGF360 genes and the CD2v genes, Yan said.
Research has shown that deleting some MGF360 genes from African swine fever creates immunity.In August, the ministry said it would test pigs for different strains of the virus as part of a nationwide investigation into illegal vaccine use.After decades of research toward producing a vaccine against the huge, complex swine fever virus, researchers around the world are focussing on live-virus vaccines - the only type to have shown any promise.One such vaccine used in Spain in the 1960s caused a chronic disease with swollen joints, skin lesions and respiratory issues in pigs that complicated efforts to eradicate African swine fever over the next three decades.Yan said he believes that people have replicated the sequences of virus strains being studied, which have been published in scientific literature, and that pigs injected with illicit vaccines based on them could be infecting others.