Betacoronavirus
Betacoronavirus is one of the four genera of coronaviruses, belonging to the family Coronaviridae, which includes other genera such as alphacoronavirus, gammacoronavirus, and deltacoronavirus. This genus primarily infects mammals and is notably the most likely to infect humans. Betacoronaviruses can cause a range of illnesses affecting the respiratory and gastrointestinal systems, with varying degrees of severity. One well-known example is HCoV-OC43, associated with mild illnesses like the common cold, though it can lead to more serious respiratory infections in vulnerable individuals.
More severe betacoronaviruses include MERS-CoV, which causes Middle East respiratory syndrome, and SARS-CoV, responsible for severe acute respiratory syndrome. The most recent and notable member of this genus is SARS-CoV-2, which led to the COVID-19 pandemic that began in late 2019, causing significant global health impacts. Various variants of SARS-CoV-2 emerged during the pandemic, some exhibiting increased transmissibility. Overall, betacoronaviruses are significant due to their zoonotic potential and impact on human health, prompting extensive scientific research to better understand and mitigate their risks.
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Betacoronavirus
Betacoronavirus is one of four genera of coronaviruses, which are enveloped viruses from the family Coronaviridae. The other genera of coronaviruses include alphacoronavirus, gammacoronavirus, and deltacoronavirus. Scientists have estimated that coronaviruses developed in roughly 8000 BCE, and betacoronaviruses developed in roughly 3300 BCE. Betacoronaviruses infect several mammals and are the most likely genus to infect humans.
Overview
Betacoronaviruses can cause diseases that affect the respiratory tract, the gastrointestinal system, or other body systems. Different virus species cause different types of illnesses and infect different hosts. Betacoronaviruses are more likely than other coronaviruses to be linked to infection in humans. Betacoronaviruses can also infect other mammals, such as bats, cows, and swine.
One common betacoronavirus is HCoV-OC43, which infects humans and causes illness that is called the common cold. (Other viruses, including two alphacoronaviruses, also cause the common cold.) Symptoms include cough, sore throat, and thin nasal discharge. Although HCoV-OC43 usually causes relatively mild illness, it can sometimes cause lower respiratory tract infections that are serious and can cause complications in individuals with asthma or other conditions. It is one of six coronaviruses known to infect humans. HCoV-OC43 is the coronavirus that most commonly infects humans.
Other betacoronaviruses have also caused illness outbreaks in humans. MERS-CoV, another betacoronavirus, causes Middle East respiratory syndrome (MERS). This respiratory disease causes serious illness in humans. As many as 35 percent of the people who contract MERS may die from it, though that percentage could be inflated because some people are asymptomatic and do not realize they are infected. MERS is a zoonotic disease, or an infectious disease that is transmitted between species. Such diseases can be transmitted from to humans from animals and to animals from humans. People most often catch MERS from infected camels but transmission between humans is possible. SARS CoV, which causes severe acute respiratory syndrome (SARS), is another betacoronavirus species that infects humans and causes serious respiratory disease.
Beginning in early 2020, the world experienced a pandemic of the virus SARS-CoV-2, which is a betacoronavirus that first emerged late in 2019. The virus causes an illness mostly of the respiratory tract, though it also affects other organ systems. The first vaccines used to prevent COVID-19, the illness caused by SARS-CoV-2, were released in late 2020 and were widely distributed throughout 2021 and 2022, which helped reduce mortality from COVID-19. However, the highly contagious disease still managed to kill nearly 7 million people worldwide by March 2023, making COVID-19 responsible for one of the deadliest pandemics in recorded history in terms of death toll. As the pandemic progressed, public health experts also noted the emergence of a number of variants of the virus, including the Delta and Omicron variants; some of these variants were more contagious than the original SARS-CoV-2 virus.
Because betacoronaviruses are the types of coronaviruses that have been most likely to infect humans, scientists have studied these viruses closely. Betacoronaviruses commonly infect other types of animals, but nearly all the hosts are mammals. Bats are common carriers of alpha- and betacoronaviruses. Scientists recognized that zoonotic illnesses caused by coronaviruses could be potentially very dangerous and have studied these animals for years.
Some betacoronaviruses infect mammals other than humans, such as antelope (AntelopeCoV), giraffes (GiCoV), horses (ECoV), mice (MHV), and swine (PHEV). These viruses commonly cause respiratory or enteric diseases, but some cause illnesses that affect other organ systems. For example, porcine hemagglutinating encephalomyelitis virus (PHEV) causes encephalomyelitis, which is inflammation of the brain and spinal cord, in swine.
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