Using deep sequencing and a "variant quantification in sewage pipeline designed for robustness," or VaQuERO, analytical pipeline, researchers from Austria and Romania profiled more than 3,400 wastewater samples collected between December 2020 and February of this year at 94 municipal catchment sites in Austria, searching for specific SARS-CoV-2 genetic variants. The team's findings — validated using epidemiological data for more than 311,000 individuals — revealed viral genetic diversity, dynamics, and diversification in the country over time. "[W]e described elevated viral genetic diversity during the Delta variant period, provide a framework to predict emerging variants, and measure the reproductive advantage of variants of concern by calculating variant-specific reproduction numbers from wastewater," the authors write, noting that the work "demonstrates the power of national-scale [wastewater-based epidemiology] to support public health and promises particular value for countries without extensive individual monitoring."