April 27, 2022


Vaccine for African swine fever passes tests for US regulatory approval



Scientists from the US Department of Agriculture's (USDA) Agricultural Research Service (ARS) announced that an African swine fever (ASF) vaccine candidate has passed an important safety test required for regulatory approval, which means it is one step closer to commercial availability, the USDA reported.


The new results show that after the USDA vaccine is injected into swine, it does not revert to its normal virulence. This test is mandatory to ensure that the vaccine's weakened form of ASF does not revert to its original state.


Manuel Borca, senior scientist at ARS, said the safety studies bring this vaccine one step closer to being available on the market.


These safety tests are required for the product to be approved for use in Vietnam and to other nations across the world. Future commercial usage will be contingent on clearance from each asking country's animal health agency.


There haven't been any ASF outbreaks in the US. In 2007, the extremely infectious ASF virus migrated from Africa to the Republic of Georgia, then surged across Central Europe and Asia until arriving in the Dominican Republic in 2021. The virus cannot be passed from swine to humans.


Douglas Gladue, senior ARS scientist, said for this vaccine candidate ASFV-G-DI177L, they deleted a gene, which makes it difficult for the virus to simply add the gene back. E said it is difficult to predict how selective pressure can cause a live attenuated vaccine to return to virulence.


When exposed to varied environmental situations, an attenuated vaccination strain retains most of its genetic composition and may alter genetically. All live attenuated vaccines are weakened variants of a virus that may still be used as a vaccine since the live vaccine virus does not cause illness and provides protection.


This study is featured in the current publication of "Viruses". NAVETCO recently chose the vaccine candidate for commercial development in Vietnam. Since 2020, NAVETCO has collaborated with ARS on ASF vaccine research and development. Once the vaccine candidate has received regulatory approval in Vietnam, further development will continue.


-      US Department of Agriculture