“ASF vaccine possible within reasonable timeframe”

11-12-2019 | | |
Photo: Vincent ter Beek
Photo: Vincent ter Beek

A vaccine against African Swine Fever could be possible ‘within a reasonable timeframe’, according to the lead researcher of the Agricultural Research Service, part of the US Department of Agriculture (USDA).

Earlier this month, news broke that a potentially new vaccine for African Swine Fever (ASF) had been created by researchers from the USDA’s Agricultural Research Service. An article appeared on the website Biorxiv, mentioning that the researchers had found a previously uncharacterised virus gene, called I177L, which when deleted completely attenuates an isolate of the ASF virus obtained from the country Georgia.

Pig Progress contacted Dr Douglas Gladue, senior scientist at Plum Island Animal Disease Center, part of the ARS. He is one of the lead scientists behind the publication.

Pig Progress: What have the reactions been to your discovery so far?

Dr Douglas Gladue: “Our results with our new experimental vaccine ASFv-G-ΔI177L have been very promising, and has characteristics that experimentally outperform our previously discovered vaccine candidates.”

Has the newly developed vaccine also been tested in farm conditions?

“ASFv-G-ΔI177L has only been tested under experimental controlled conditions.”

What about scaling up production at this stage?

“Our vaccine is still in the experimental stages and will require regulatory approval; this approval varies between countries. Currently there is no stable cell line capable of supporting ASFv vaccine growth, growing of our vaccine currently relies on isolation of primary swine macrophages.”

There have already been quite a few people asking me when this vaccine would be available for use. Perhaps its early days, but could you say anything about that at all at this stage?

“ASFv-G-ΔI177L is still in the experimental stage, so far it has been very promising, the time frame for regulatory approval and commercialisation is unknown, but we believe it could be possible in a reasonable timeframe.”

Has there been contact with commercial pharmaceutical parties about marketing it? If so, which?

“Currently we do not have a commercial partner for ASFv-G-ΔI177L.”

In the light of the developments in Europe and Asia, I could imagine there is massive interest from many corners of the world. Has there been contact with authorities of countries?

“None that I am currently aware of.”

What made you look into this particular gene?

“ASF has over 150 predicted genes, the exact number of genes varies by isolate. Very few of these genes have been studied experimentally, with some having a predicted function due to similarity with other genes (cellular or viral). Using a bioinformatics pipeline, we ranked genes with a high likelihood of being important for immune evasion. Our top-3 candidates were genes Ep152R, L83L, and I177L. Ep152R we determined was an essential gene and could not be deleted (PMID 27497620). L83L we were able to delete but there was no effect on virus virulence (PMID 29605728). I177L, our 3rd candidate, when deleted was fully attenuated and became our vaccine candidate.”

Read more about African Swine Fever in our special ASF section.

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ter Beek
Vincent ter Beek Editor of Pig Progress / Topic: Pigs around the world