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January 20, 2023
Content Overview
SARS-CoV-2 is a beta coronavirus that causes COVID-19 in people.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) was identified in China in 2019, then confirmed by the World Health Organization (WHO) in 2020.

As the name indicates, this coronavirus is related to the SARS beta coronavirus (SARS-1) that caused fatal outbreaks in 2002-2003. However, it is not the same virus, says the U.S. Centers for Disease Control and Prevention (CDC).

In molecular epidemiology, a study published on May 4, 2021, found the progenitor genome (proCoV2) is the mother of known SARS-CoV-2 coronaviruses. These researchers estimate that the SARS-CoV-2 progenitor was in circulation several weeks before the first genome sequenced in China, known as Wuhan-1, stated Sayaka Miura, a study's senior author.

SARS-CoV-2 Infectious Rate 2023

SARS-CoV-2 sequences by variant, as of January 12, 2023, was posted by World in Data. In addition, the journal Nature Medicine published a study on January 2, 2023, Infectiousness of SARS-CoV-2 breakthrough infections and reinfections during the Omicron wave, as did The Lancet Infectious Diseases.

The CDC recommends using the COVID Data Tracker to determine the impact of COVID-19 on local communities.

SARS-CoV-2 Variants of Concern 2023

The coronavirus that causes COVID-19 is mutating, which is expected as viruses mutate as they spread, stated the U.S. CDC. The original SARS-CoV-2 strain, detected in Wuhan, China, in December 2019, is the L virus strain. This human coronavirus (hCOV) has since mutated. 

The WHO, in collaboration with partners, expert networks, national authorities, institutions and researchers, has been monitoring and assessing the evolution of SARS-CoV-2 since January 2020. As a result, an updated listing of variants of concern was posted in January 2023. And the CDC posts SARS-CoV-2 Variant Classifications and Definitions at this link.

SARS-CoV-2 Coronavirus FAQs

NOTE: This page's content is sourced from the CDC, WHO,, and the Precision Vax network of websites. Healthcare providers fact-checked this information.