Genetic diversity of rotavirus A in Argentina during 2019-2022: detection of G6 strains and insights regarding its dissemination.

One of the challenges associated with introducing a vaccine is monitoring its impact through clinical and molecular surveillance. The aims of this study were to analyze the genetic diversity of rotavirus A in Argentina between 2019 and 2022 and to assess the phylogenetic and phylodynamic features of the unusual G6 strains detected. A significant decline in the Wa-like genogroup strains was observed, and G6 strains were detected for the first time in Argentina, in association with P[8] and P[9]. Spatiotemporal analysis showed that the G6-lineage I strains detected recently in Argentina and Brazil might have emerged from European strains. This study provides recent evidence of the genetic diversity of rotaviruses in isolated cases. It is considered important to support continuous surveillance of rotavirus in the post-vaccine scenario, mainly to evaluate potential changes that may occur after the COVID-19 pandemic.