Scientists from the U.S. Department of Agriculture (USDA) announced that they have developed a vaccine that is highly effective against African swine fever (ASF) that has killed millions of pigs throughout Asia, particularly in China, and is spreading towards Europe.
Live attenuated vaccine tested on animals at Plum Island, New York has been highly effective. The live attenuated vaccine was developed by deleting a gene, called I177L, which was thought to be the gene involved in immunomodulation of the virus.
Douglas Glaude
Dr. Douglas Gladue, Senior Scientist at Plum Island Animal Disease Center, and one of the co-inventors of the vaccine relayed the official answer given by USDA to Feed Planet magazine’s questions. “Our ASFV- ΔI177L vaccine is part of the Agricultural Research Service’s (ARS) portfolio of live attenuated vaccines for ASF that are based on deleting genes in ASFV. ASFV-ΔI177L was invented by Drs. Douglas Gladue and Manuel Borca, and is the most promising candidate vaccine to date. What differentiates ASFV- ΔI177L from our other platforms, is that this candidate vaccine offers 100% protection at low doses of 102 and has no residual virulence even at high doses of 106. ASFV- ΔI177L was observed not to shed to unvaccinated animals (meaning the vaccine ASFV- ΔI177L does not transmit from animal to animal). ASFV- ΔI177L vaccinated animals also achieve sterile immunity (meaning that when exposed to WT virus there is no WT virus replication observed in vaccinated animals). However, ASFV- ΔI177L is still in the experimental stage and has only been tested under experimental conditions,” said the text about the significance of the vaccine.
The answers went on about whether this vaccine will be able to root out ASF completely as follows: “Our ASFV-G-ΔI177L vaccine is capable under experimental conditions to be 100% effective at low doses, and has no residual virulence at high doses, so it would be a candidate vaccine that in theory could be mass produced. However, currently the vaccine only grows in primary swine macrophages, which limits its scalability. Having an effective vaccine is part of any eradication program, but only one aspect. For example we have had a Polio vaccine since the 60’s and Polio is still not eradicated.”