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. 2021 May 14;70(19):717-718.
doi: 10.15585/mmwr.mm7019e2.

Identification of and Surveillance for the SARS-CoV-2 Variants B.1.427 and B.1.429 - Colorado, January-March 2021

Lindsey Martin Webb  1 , Shannon Matzinger  1 , Christopher Grano  1 , Breanna Kawasaki  1 , Ginger Stringer  1 , Laura Bankers  1 , Rachel Herlihy  1
Affiliations

Identification of and Surveillance for the SARS-CoV-2 Variants B.1.427 and B.1.429 - Colorado, January-March 2021

Lindsey Martin Webb et al. MMWR Morb Mortal Wkly Rep. .

Abstract

The B.1.427 and B.1.429 variants of SARS-CoV-2, the virus that causes COVID-19, were first described in Southern California on January 20, 2021 (1); on March 16 they were designated variants of concern* (2). Data on these variants are limited, but initial reports suggest that, compared with other lineages, they might be more infectious (1,2), cause more severe illness (2), and be less susceptible to neutralizing monoclonal antibody products such as bamlanivimab, an investigational treatment for mild-to-moderate COVID-19 (1-3). On January 24, the Colorado Department of Public Health and Environment (CDPHE) identified the first Colorado case of COVID-19 attributed to these variants. B.1.427 and B.1.429 were considered a single variant described as CAL.20C or B.1.427/B.1.429 in the 20C clade (1,3); in this report "B.1.427/B.1.429" refers to B.1.427 or B.1.429 lineage, including those reported as B.1.427/B.1.429 without further differentiation.

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Conflict of interest statement

All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

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