Abstract
The history of coronaviruses is an account of the discovery of coronaviruses and the diseases they cause. It starts with a report of a new type of upper-respiratory tract disease among chickens in North Dakota, US, in 1931. The causative agent was identified as a virus in 1933. By 1936, the disease and the virus were recognised as unique from other viral diseases. The virus became known as infectious bronchitis virus (IBV), but later officially renamed as Avian coronavirus. A new brain disease of mice (murine encephalomyelitis) was discovered in 1947 at Harvard Medical School in Boston. The virus was called JHM (after Harvard pathologist John Howard Mueller). Three years later a new mouse hepatitis was reported from the National Institute for Medical Research in London. The causative virus was identified as mouse hepatitis virus (MHV), later renamed Murine coronavirus. In 1961, a virus was obtained from a school boy in Epsom, England, who was suffering from common cold. The sample, designated B814, was confirmed as novel virus in 1965. New common cold viruses (assigned 229E) collected from medical students at the University of Chicago were also reported in 1966. Structural analyses of IBV, MHV, B18 and 229E using transmission electron microscopy revealed that they all belong to the same group of viruses. Making a crucial comparison in 1967, June Almeida and David Tyrrell invented the collective name coronavirus, as all those viruses were characterised by solar corona-like projections (called spikes) on their surfaces. Other coronaviruses have been discovered from pigs, dogs, cats, rodents, cows, horses, camels, Beluga whales, birds and bats. As of 2022, 52 species are described. Bats are found to be the richest source of different species of coronaviruses. All coronaviruses originated from a common ancestor about 293 million years ago. Zoonotic species such as Severe acute respiratory syndrome-related coronavirus (SARS-CoV), Middle East respiratory syndrome-related coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a variant of SARS-CoV, emerged during the past two decades and caused the first pandemics of the 21st century.