Researchers working on vaccine for virus dubbed the “most significant threat to pork production in the whole world”

Covid vaccine development has held the spotlight this year, but it isn’t the only disease researchers have been urgently working to understand. Some Kansas researchers are focused on an even deadlier disease.

Luckily, it poses no health risks to humans and only affects pigs.

“I think African swine fever virus in general is arguably the largest or most significant threat to pork production in the whole world because of how concerning this virus is and its recent introduction into new countries,” Megan Niederwerder, an assistant professor in the department of diagnostic medicine and pathobiology at Kansas State University said.

While the virus has been found in countries in Africa, Asia, and Europe, it hasn’t been observed in the United States yet. On Wednesday however, the United States Department of Agriculture confirmed the presence of African swine fever in the Dominican Republic, a Caribbean nation. The disease hadn’t been detected in the Americas for nearly 40 years, according to the National Pork Producers Council, a U.S. industry group.

If it were to come to the United States, it could be devastating to the pork industry. According to a study funded by Iowa State University and BarnTools, a digital biosecurity platform company, an outbreak of the disease that wasn’t quickly controlled could cost up to $50 billions in losses for the pork industry.

“Part of the issue of African swine fever is there’s currently no therapeutics or treatments available for it and there’s also no commercially available vaccines for it,” said Jayden McCall, a veterinary student at Kansas State University who recently won a fellowship to study potential vaccines for the virus. “It tends to have about 100% mortality in any herds that it infects.”

According to McCall, the large genome of the virus makes creating a vaccine especially difficult. Unlike influenza, which has 8 proteins, African swine fever virus has more than 150 proteins that researchers need to understand to make a potential vaccine.

In addition, researchers don’t have knowledge about the virus from studying similar viruses like they did for creating the coronavirus vaccine.

“There are many viruses within that family [coronavirus] and so you can sort of take what you know about one and apply it to a new one or an emerging one,” Niederwerder said. “In the case of African swine fever virus, there is no other virus in that family.”

To create a potential vaccine, McCall and his colleagues will expose white blood cells from pigs to different African swine fever virus proteins and see which ones the white blood cells react to. By doing so, they hope to narrow down the more than 150 proteins to only a few which could then be tested in a potential vaccine. Because this method only uses part of the virus rather than the full virus, the resulting vaccines are referred to as subunit vaccines.

“Subunit vaccines have shown to be more promising as far as delivering efficacy while also being a lot safer because again you’re not giving alive or killed virus in any sort of formation,” McCall said. “The problem is, you need to know which of those proteins confer protective immunity to train the immune system.”

Developing vaccines is only part of the solution, however. Preventing African swine fever virus from entering a new country is just as important.

According to Niederwerder, African swine fever virus could enter through swine feed products as the most recent transboundary virus to affect pigs, porcine epidemic diarrhea virus, was hypothesized to in 2013 or through contaminated pork-products.

While a human could eat infected pork products without getting sick, the same isn’t true of the wild boars which are found in many southern states and some southeastern Kansas counties. That’s the presumed route African swine fever virus entered Germany last year, limiting the country’s pork exports, and has since spread to commercial farms.

“Whenever a country gets African swine fever reported either in it’s wild boar population or domestic swine population, they cannot export their pork very well,” McCall said.

If an outbreak does happen here, even non-pig farmers might feel the consequences due to possible price increases. The 2019 outbreak in China led to the death of half of the country’s pigs, causing pig prices to more than double there.

“Do you like bacon being $3 for a box of it? If you do then you’re going to be at least somewhat invested in this because if this does get into the US, that $3 box of bacon is going to be a lot more potentially,” McCall said.