A Revised Classification of Vesicular Stomatitis Virus (VSV) Genotypes and Subtypes.

Vesicular stomatitis virus (VSV) causes clinical disease in livestock that mimics Foot-and-Mouth Disease, necessitating its status as a reportable pathogen to the World Organization for Animal Health. Given the importance of accurate classification for epidemiological surveillance, this study aims to update VSV taxonomic organization using whole-genome sequence criteria to better monitor disease dynamics. Using phylogenetic analysis and the Species Demarcation Tool (SDT), we analyzed pairwise identity across publicly available sequences, constructing a rooted maximum likelihood tree to cluster strains based on robust genetic identity scores. The results demonstrate that nucleotide divergences exceeding 30% define distinct species within the Vesiculovirus genus. Within a species, divergences between 10% and 30% successfully delineate genotypes, while differences between 6% and 10% identify specific subtypes. These quantitative benchmarks provide a precise framework for viral classification, significantly enhancing genomic surveillance and the ability to track the evolution and transmission of VSV genotypes and subtypes across diverse geographic regions.