Chinese Harbin Institute: New ASF vaccine is effective

The discovery was made public in a scientific article published in Science China Life Sciences and also news agency Bloomberg reported on the finding. The Harbin institute, overseen by the Chinese Academy of Agricultural Sciences (CAAS), said deleting a series of genes from the virus created a live vaccine with reduced virulence.

On its website, the Harbin Veterinary Research Institute said, “The vaccine is currently the most promising vaccine for industrial application, and will provide important technical means for the effective prevention and control of African Swine Fever in China and related countries.” So far, it did not mention as to when a commercial vaccine might be available.

First ASF virus isolate as backbone

The researchers used China’s first ASF virus isolate, called HLJ/18 as the backbone and constructed a series of recombinant viruses with different gene deletions using homologous recombination technology. In total 6 recombinant viruses were made and put to the test. Through systematic pathogenicity, immunogenicity and immunoprotective tests in pigs, a virus with 7 gene deletions (HLJ/-18-7GD) was selected because it met the safety standards for live attenuated vaccines, which can be used in pigs.

Trials included various rounds with (Specific Pathogen Free) pigs as well as sows.

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ASF virus could not replicate

The article on the Harbin Institute website said, “Even after the newly developed vaccine was inoculated to pigs at the highest dose, the vaccine virus could not replicate in parenchymal organs, did not produce viraemia, and only limitedly replicated in some lymph nodes. It was completely cleared by the body in about 2 weeks and could not be sustained in the body.”

The article continued to say, “In addition, the vaccine also has good safety for pregnant sows. Vaccination in the early, middle and late stages of pregnancy cannot cause abortion. The rate of piglets born after immunisation is no different from that of the unimmunised control group.

In their research abstract, the scientists conclude by saying: “Our study shows that HLJ/-18-7GD is a safe and effective vaccine against ASFv, and as such is expected to play an important role in controlling the spread of ASFv.”

The research article was authored by Weiye Chen, Dongming Zhao, Renqiang Liu, Zilong Wang, Fang Li, Dan Shan, Hefeng Chen, Jiwen Zhang, Lulu Wang, Zhiyuan Wen, Xijun Wang, Jinxiong Liu, Harbin Veterinary Research Institute, China; Xijun He, Xianfeng Zhang and Yuntao Guan, National High Containment Laboratory for Animal Diseases Control and Prevention, Harbin, China. Lead author Zhigao Bu is connected to both organisations.