COVID Variants of Concern in the US

[Joseph Arabasz MD]

Cennimo et al

06/2021

Virology

The genome of SARS-CoV-2 was first posted by health authorities soon after the initial detection, facilitating viral characterization and diagnosis. The CDC analyzed the genome from the first US patient who developed the infection on January 24, 2020, concluding that the sequence is nearly identical to the sequences reported. SARS-CoV-2 is a group 2b beta-coronavirus that has at least 70% similarity in genetic sequence to SARS-CoV. Like MERS-CoV and SARS-CoV, SARS-CoV-2 originated identically  

A new virus variant emerges when the virus develops 1 or more mutations that differentiate it from the predominant virus variants circulating in a population. The CDC surveillance of SARS-CoV-2 variants includes US COVID-19 cases caused by variants. The site also includes which mutations describes particular variants. The CDC has launched a genomic surveillance dashboard and a website tracking US COVID-19 case trends caused by variants. Researchers are studying how variants may alter the extent of protection by available vaccines.

Mutations

Viral mutations may naturally occur anywhere in the SARS-CoV-2 genome. Unlike the human genome, which is slow to mutate, RNA viruses can readily, and quickly, mutate. A mutation may alter the viral function (eg, enhance receptor binding), or may have no discernable function.