04/22/2021: Lab Advisory: CDC Classifies SARS-CoV-2 Variant B.1.526.1 a Variant of Interest

CDC's Laboratory Outreach Communication System (LOCS)

Audience: Clinical Laboratory Professionals

Level: Laboratory Advisory:

On April 21, 2021, CDC classified SARS-CoV-2 variant B.1.526.1 as a variant of interest. This variant was first detected in New York in October 2020. Investigations are underway to further characterize B.1.526.1 sub-lineage viruses and their potential impact on current vaccines and therapeutics.


SARS-CoV-2 variants can be categorized into the following three classes based on a Variant Classification scheme developed by a US government interagency group:

A variant of interest might require one or more appropriate public health actions, including

  • Enhanced sequence surveillance
  • Enhanced laboratory characterization
  • Epidemiological investigations to assess how easily the virus spreads to others, the severity of disease, the risk of reinfection, and whether currently authorized vaccines offer protection

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Thank you,

Laboratory Outreach Communication System | Division of Laboratory Systems (DLS)

Center for Surveillance, Epidemiology, and Laboratory Services (CSELS)

Centers for Disease Control and Prevention (CDC)