journals.plos.org
Emergence of a novel GII.17 variant is associated with immune evasion rather than an altered HBGA-binding profile
Author summary Noroviruses are the leading cause of acute gastroenteritis worldwide and are responsible for large numbers of outbreaks each year. New norovirus variants can spread rapidly when they are no longer well recognized by existing immunity in the population. In 2024, a new GII.17 variant became increasingly common in several regions, raising questions about why this virus was able to spread so successfully. In this study, we compared this new variant with other GII.17 viruses that circulated in 2005, 2014, and 2015. We examined how well these viruses could attach to molecules and tissues in the human gut and how well they were recognized by antibodies in human serum samples collected over time. We found that the 2024 variant was less well recognized by existing antibodies than some earlier strains, suggesting that it had changed in ways that may help it evade prior immunity. In contrast, its ability to bind to human gut-related targets was broadly similar to that of recent other variants. Together, our findings suggest that changes in immune recognition, rather than major changes in binding specificity, contributed to the recent emergence of this GII.17 variant.
