WASHINGTON — Researchers have reclassified the number of African swine fever (ASF) virus strains from 25 to only six unique genotypes, announced the US Department of Agriculture’s Agricultural Research Service (ARS).

With this new classification, scientists may be able to better develop vaccines that match the different strains circulating in ASF infected areas.

“Previously, 25 different virus genotypes were identified across the globe,” said Douglas Gladue, senior ARS scientist. “Our research team recently re-evaluated all the publicly available virus DNA sequence and found that the majority of genotypes (genetic makeup) originally identified as novel were not correctly identified nor compared to already existing ASFV genotypes. Based on this analysis, there are actually fewer unique genotypes than the ASF research community believed, and that means that there is less diversity of ASFV affecting communities across the globe. This information is important as it may reduce the number of vaccines previously thought to be needed to protect against all ASFV genotypes.”

Leading up to the reclassification, ARS researchers re-analyzed over 12,000 historical and current virus isolates that were produced from ASF labs worldwide. They relied on the computing power of SciNet, ARS’ supercomputer cluster for solving agricultural big data problems.

The United States has continued to remain free of ASF, while the virus spread from Africa to the Republic of Georgia in 2007 and later swept across Europe, the Dominican Republic and Asia, before reaching South Africa in early 2023. ASF poses a challenge to the global swine industry as it has led to significant economic losses.