U.S. surveillance shows XBB and JN.1 Omicron descendants dominated SARS-CoV-2 circulation from May 2023 to September 2024What COVID variants are circulating in the U.S.?

A surveillance report from the United States tracked SARS-CoV-2 variant circulation from May 2023 to September 2024. The report provided variant proportion estimates, finding that circulating lineages during this period were primarily comprised of descendants of Omicron variants XBB and JN.1. No specific intervention, comparator, or sample size was reported for this descriptive analysis.

No quantitative effect sizes, absolute case numbers, or statistical measures (p-values, confidence intervals) were provided for the reported lineage trends. The report did not include data on clinical outcomes, severity, or transmissibility associated with the identified variants.

Safety, tolerability, and adverse event data were not reported, as this was a surveillance summary rather than a clinical study. The report did not list specific methodological limitations, but its descriptive nature means it cannot establish causality or quantify the public health impact of the observed trends.

For clinical practice, this report provides a snapshot of viral evolution but offers no direct guidance on treatment or prevention. The findings are relevant for understanding the shifting genetic landscape of SARS-CoV-2 but should be interpreted alongside clinical and epidemiological data assessing variant-specific outcomes.