A vaccine candidate for African swine fever (ASF) has passed a safety test for regulatory approval, moving the vaccine a step closer to commercial use.
USDA Agricultural Research Service (ARS) scientists said passing the test is a critical milestone for the ASF vaccine candidate. The test shows the vaccine’s weakened form of the ASF virus does not revert to its original state once injected into swine.
“It is very hard to predict how selective pressure can cause a live attenuated vaccine to return to virulence,” said senior ARS scientist Douglas Gladue. “In the case of this particular vaccine candidate, ASFV-G-DI177L, we deleted a gene, which makes it difficult for the virus to simply add the gene back.”
While the safety tests are necessary to gain approval for use across the world, future commercial use will depend on approval from an individual country’s department of animal health. There have not been any ASF outbreaks in the U.S., but the virus has decimated hog herds in other parts of the world, including Central Europe and Asia and the Dominican Republic.
“For low- and middle-income countries, the availability of a vaccine is paramount, as depopulating affected swine herds is not logistically or economically feasible,” read the research article published in the scientific journal Viruses.
Results show the vaccine candidate was given to pigs 6-8 weeks of age, was safe and lacked the ability to induce local and systemic disease. Although a low level of shedding from vaccinated animals could be detected for a few days, the vaccine virus was shown to remain genetically stable.
The vaccine candidate was selected by National Veterinary Joint Stock Company for commercial development in Vietnam. The company has partnered with ARS on ASF vaccine research and development since 2020, and further development will continue once the candidate receives regulatory approval from Vietnam. — Anna Miller, WLJ managing editor
