Coronaviruses are a group of related RNA viruses that affect mammals and birds, causing respiratory tract infections. Human coronaviruses range from causing mild common colds to lethal diseases like SARS, MERS, and COVID-19. In other animals, they can cause diarrhea (cows and pigs), hepatitis and encephalomyelitis (mice).
1931: First Detailed Report of Avian Coronavirus
The first detailed report of a coronavirus infection in animals was made in 1931 by Arthur Schalk and M.C. Hawn, describing a respiratory infection affecting chickens in North Dakota.
1933: Isolation of Infectious Bronchitis Virus (IBV)
Leland David Bushnell and Carl Alfred Brandly successfully isolated the infectious bronchitis virus (IBV) in 1933.
1937: First IBV Strain Cultivated
The first cultivation of the IBV, using what became known as the Beaudette strain, was done by Charles D. Hudson and Fred Robert Beaudette in 1937.
1960: Divergence of Alpaca and Human Coronavirus 229E
Alpaca coronavirus and human coronavirus 229E are thought to have diverged sometime before 1960.
1961: Discovery of Human Coronavirus B814
Researchers at the Common Cold Unit in the UK discovered a novel common cold virus, B814, which was later identified as a human coronavirus. Its unique characteristics prevented cultivation using standard techniques available at the time.
1962: Isolation of Human Coronavirus 229E
In 1962, researchers at the University of Chicago isolated and grew another human coronavirus strain, 229E, from medical students using kidney tissue culture. This, along with B814, provided evidence for ether-sensitive, lipid-enveloped viruses causing the common cold.
1965: Successful Cultivation of B814
David Tyrrell and Bynoe successfully cultivated the B814 virus in 1965 through serial passaging in human embryonic trachea organ culture, paving the way for further research on human coronaviruses.
1967: Morphological Similarities of Coronaviruses Established
June Almeida's electron microscopy work in 1967 revealed the morphological similarities between IBV, B814, and 229E, highlighting the distinctive club-like spikes characteristic of coronaviruses. Further research at NIH isolated OC43, another coronavirus with the same distinctive spikes.
1968: "Coronavirus" name coined
In 1968, the term "coronavirus" was first used in print in the journal Nature by a group of virologists to describe the virus family based on their crown-like appearance under electron microscopy. This distinctive "corona" is formed by the viral spike peplomers on the virus's surface.
1971: Coronavirus Genus Accepted
In 1971, the scientific name "Coronavirus" was officially accepted as a genus name by the International Committee for the Nomenclature of Viruses.
1986: Divergence of Bat and SARS Coronaviruses
The most closely related bat coronavirus and SARS-CoV are estimated to have diverged around 1986.
2003: WHO identifies SARS Coronavirus
Following the SARS outbreak that began in 2002 in Asia, the WHO, in 2003, officially identified the novel coronavirus, later named SARS-CoV, as the causative agent of SARS. Over 8,000 people across 29 different countries and territories were infected with SARS and at least 774 people died as a result of contracting the virus.
2003: Discovery of SARS-CoV and HCoV NL63
In 2003, the SARS coronavirus (SARS-CoV), the causative agent of severe acute respiratory syndrome (SARS), and HCoV NL63 were discovered.
2003: SARS Outbreak
In 2003, the SARS coronavirus was identified as the cause of severe acute respiratory syndrome (SARS).
2004: Discovery of HCoV HKU1
HCoV HKU1 was discovered in 2004, adding to the expanding list of known human coronaviruses.
2009: Coronavirus Genera Split
The Coronavirus genus was split into four new genera: Alphacoronavirus, Betacoronavirus, Deltacoronavirus, and Gammacoronavirus in 2009 to accommodate the rising number of new species discovered.
September 2012: Novel Coronavirus 2012 Identified
In September 2012, a new type of coronavirus was identified, initially called Novel Coronavirus 2012. The World Health Organization issued a global alert soon after the identification of the virus.
October 2013: MERS Cases and Deaths in Saudi Arabia
By October 2013, Saudi Arabia had reported 124 MERS cases with 52 deaths.
2013: MERS-CoV Identified
In 2013, MERS-CoV, which causes Middle East respiratory syndrome (MERS), was identified.
May 2014: First U.S. Cases of MERS-CoV
In May 2014, the only two cases of MERS-CoV in the U.S. were recorded, both of which survived. The virus had been previously sequenced by the Dutch Erasmus Medical Centre and named HCoV-EMC, later officially becoming Middle East respiratory syndrome coronavirus (MERS-CoV).
May 2015: MERS-CoV Outbreak in South Korea
A large outbreak of MERS-CoV occurred in May 2015 in South Korea, originating from a traveler who had been to the Middle East. This marked one of the biggest outbreaks outside that region.
2018: Discovery of Canine Coronavirus Infecting Humans
In 2018, during a study of archived samples from Malaysian viral pneumonia patients, virologists discovered a strain of canine coronavirus that had infected humans.
December 2019: Global MERS-CoV Cases and Fatalities
By December 2019, the global number of MERS-CoV cases reached 2,468, with 851 fatalities, representing a mortality rate of about 34.5%.
2019: Emergence of SARS-CoV-2
SARS-CoV-2, the virus responsible for the COVID-19 pandemic, was discovered in 2019.
2020: 45 Coronavirus Species
As of 2020, 45 distinct coronavirus species have been officially recognized.
March 2023: COVID-19 Pandemic Statistics and Wuhan Strain Analysis
As of March 2023, the COVID-19 pandemic had resulted in at least 6,881,955 confirmed deaths and over 676,609,955 confirmed cases. The Wuhan strain, identified as a new Betacoronavirus from group 2B, shares about 70% genetic similarity with SARS-CoV and 96% similarity with a bat coronavirus, suggesting a possible bat origin.