A seven-gene-deleted African swine fever virus is safe and effective vaccine in pigs
African swine fever (ASF) is a devastating infectious disease in swine and has been catastrophic for the global pig industry. In 2018, ASFV was transmitted to pigs in China and ten other Asian countries, which damaged the pork industry in these areas. The fact demonstrates that ASF is hard to control only by culling infected pigs in China, and the development and application of an efficacious vaccine is urgently needed. Different vaccine strategies for ASF have been evaluated in past decades. Some gene-deleted attenuated ASFVs—but not Inactivated vaccines, DNA vaccines, subunit vaccines, and adenovirus-vectored vaccines—have shown potential as ASF vaccines, while it is not known if they could convert to more virulent strains during their replication in pigs. In the present study, Chen and his colleagues used the Chinese ASFV HLJ/18 as a backbone and generated a series of gene-deleted viruses, and demonstrated that HLJ/-18-7GD (genes encoding MGF505-1R, MGF505-2R, MGF505-3R,...