Recombined African Swine Fever Virus Detected in China Raises New Concerns

Farmscape for July 18, 2023

A recombined African Swine Fever virus identified in China may prove to be more difficult to detect and less controllable through vaccination.
The Swine Health Information Center's July eNewsletter discusses reports out of China outlining evidence of a recombination of African Swine Fever genotype 1 and genotype 2 viruses.
SHIC Executive Director Dr. Paul Sundberg says, when you get two viruses together, even two genotypes of the same virus, infecting their hosts there is an opportunity for genetic material to transfer from one to the other.

Quote-Dr. Paul Sundberg-Swine Health Information Center:
One of the things that scientists have looked at is the cross protection of the different genotypes.
If, for example, genotype 2 which is virulent and traveling around the world can be prevented by vaccination with a genotype 1, which is less virulent and more stable then perhaps there's an opportunity to use that genotype 1 to dampen or even prevent genotype 2.
What scientists have found out is that that doesn't happen.
There's not cross protection between the genotypes so the issue of our vaccinations being effective against genotype 2 when there's a recombination of 1 and 2 is still a major question.
We don't know that.
It hasn't been tested.
If the current vaccine prototype has some efficacy and safety against the genotype 2 it's not known at this yet if they'd be just as safe and just as effective against any recombination and if not, that could give an opportunity for this new recombinant virus to continue to spread and continue to cause trouble.

Dr. Sundberg says this recombination could result in a virus that's as transmissible as genotype 2 while being less virulent and more difficult to detect than would be genotype 2 by itself.
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Bruce Cochrane.

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