Coronavirus 2023

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Last reviewed
July 19, 2023
Content Overview
Human coronaviruses are the second leading cause of the common cold and variants in 2023.

Coronavirus Overview 2023

Coronaviruses (CoV) are important pathogens of vertebrates that can cause respiratory, enteric, and systemic diseases in humans and animals, says the U.S. NIH. A recent study reported that human coronaviruses (hCOV) were cultured in the 1960s from nasal cavities of people with the common cold. Coronaviruses are the second leading cause of the common cold after rhinoviruses. The subfamily is divided into four genera:    Alphacoronavirus,  Betacoronavirus,  Gammacoronavirus,  and  Deltacoronavirus. Betacoronaviruses have relatively large RNA genomes of around 30 kb in size. According to the U.S. Centers for Disease Control and Prevention (CDC), people commonly get infected with human betacoronaviruses 229E, NL63, OC43, and HKU1. 

The International Committee for the Taxonomy of Viruses approved naming more than 40 coronaviruses. The four main sub-groupings of coronaviruses are alpha, beta, gamma, and delta. Beta coronaviruses are microscopic balls covered in spikes that encapsulate a central core of genetic material. The virus must infect cells to replicate and do this, and it must first attach to the cells.

SARS-CoV-1 Coronavirus

SARS-CoV-1 was first reported in Asia in February 2003. By the time the outbreak was contained in July 2003, SARS had affected about 8,000 people in 29 countries and resulted in 774 related fatalities, reported GAVI.

SARS-CoV-2 Beta Coronavirus

The U.S. CDC and the NIH reported that SARS-CoV-2 originated in 2019 but has now spread internationally, impacting most countries. On February 5, 2020, JAMA published a study from genetic sequencing data, showing this betacoronavirus shares 79.5% of the genetic sequence with SARS-CoV-1 and had 96.2% homology to a bat coronavirus.

This finding indicates that SARS-CoV-1 and SARS-CoV-2 are not the same coronaviruses.

MERS-CoV Coronavirus

The emergence of the betacoronavirus Middle East Respiratory Syndrome (MERS) was first reported in the Kingdom of Saudi Arabia in 2012. Humans are infected with MERS-CoV from direct or indirect contact with dromedaries. In addition, MERS-CoV has demonstrated the ability to transmit between humans.

An importation of MERS into the Republic of Korea in 2015 led to the largest MERS outbreak outside of the Middle East. By the outbreak's end, 186 laboratory-confirmed cases (185 in the Republic of Korea and 1 in China) and 38 deaths had been recorded.

Note: This content is sourced from the U.S. CDC, the WHO, and research studies and is reviewed by health professionals.