USA reports progress on vaccine

Scientists at the Agricultural Research Service (ARS), part of the U.S. Department of Agriculture (USDA), said the test was required for regulatory approval. "This is a critical milestone for the ASF vaccine candidate. These safety studies bring this vaccine one step closer to market availability," ARS senior scientist Manuel Borca said.

The safety studies are necessary to obtain the planned approval for use in Vietnam and eventually in other countries around the world, he said. However, future commercial use would depend on approval by the relevant authority in each applicant country, he said. The potential vaccine, called ASFV-G-DI177L, has had a gene removed that is important for its replication. This allows it to confer immunity on the host organism but not cause disease. However, like all attenuated vaccine strains, the pathogen retains much of its genetic material and can continue to change due to environmental factors.

The safety test (reversion to virulence) now performed by ARS is required to ensure that the vaccine virus does not regain its virulence under field conditions. This was confirmed by the test. The vaccine candidate was recently selected by the National Veterinary Joint Stock Company (NAVETCO) in Vietnam for commercial development in its own country. NAVETCO has been collaborating with ARS on ASF vaccine research and development since 2020. Further development will continue once the vaccine candidate receives regulatory approval from Vietnam.