SARS-CoV-2 Variant Proportions

Principal Investigator(s):  View help for Principal Investigator(s) United States Department of Health and Human Services. Centers for Disease Control and Prevention

Version:  View help for Version V1

Name File Type Size Last Modified
SARS-CoV-2_Variant_Proportions_20251013.csv text/csv 420.8 MB 10/13/2025 11:52:AM

Project Citation: 

United States Department of Health and Human Services. Centers for Disease Control and Prevention. SARS-CoV-2 Variant Proportions. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2025-10-13. https://doi.org/10.3886/E238812V1

Project Description

Project Title:  View help for Project Title SARS-CoV-2 Variant Proportions
Summary:  View help for Summary To identify and track SARS-CoV-2 variants, CDC uses genomic surveillance. CDC's national genomic surveillance system collects SARS-CoV-2 specimens for sequencing through the National SARS-CoV-2 Strain Surveillance (NS3) program, as well as SARS-CoV-2 sequences generated by commercial or academic laboratories contracted by CDC and state or local public health laboratories. Viral genomic sequences are analyzed and classified as a particular variant. The proportions of variants in a population are estimated nationally, by HHS region, and by jurisdiction. Sequences contributed to CDC’s national genomic sequencing and bioinformatics efforts fuel this U.S. genomic surveillance system established to identify and monitor the spread of SARS-CoV-2 variants.

These data appear on the CDC website at the following URL: https://www.cdc.gov/covid/php/variants/variants-and-genomic-surveillance.html


For more information on how these data are generated and used to provide estimates of variant proportions, please see the following references:


  • Paul P, France AM, Aoki Y, et al. Genomic Surveillance for SARS-CoV-2 Variants Circulating in the United States, December 2020–May 2021. MMWR Morb Mortal Wkly Rep 2021;70:846–850. DOI: http://dx.doi.org/10.15585/mmwr.mm7023a3

  • Lambrou AS, Shirk P, Steele MK, et al. Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants — United States, June 2021–January 2022. MMWR Morb Mortal Wkly Rep 2022;71:206–211. DOI: http://dx.doi.org/10.15585/mmwr.mm7106a4
Original Distribution URL:  View help for Original Distribution URL https://data.cdc.gov/Laboratory-Surveillance/SARS-CoV-2-Variant-Proportions/jr58-6ysp/about_data

Scope of Project

Subject Terms:  View help for Subject Terms COVID-19; surveillance; variant
Geographic Coverage:  View help for Geographic Coverage United States
Time Period(s):  View help for Time Period(s) 2021 – 2025
Data Type(s):  View help for Data Type(s) clinical data; medical records
Collection Notes:  View help for Collection Notes Rows: 4.36 M
Columns: 10
Each row is a Estimates of SARS-CoV-2 variants as a proportion of surveillance sequencing

Data downloaded 2025-10-13.


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V1 [2025-10-13]

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