Corona virus history

Scientists have learned about coronavirus since the 1960s. Yet it has scarcely achieved broader attention in the past half-century.

One reason was in 2003, when there was an outbreak of serious acute respiratory syndrome coronavirus (SARS-CoV) in mainland China and Hong Kong.

That was the 2012 outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia, the United Arab Emirates and the Republic of Korea, among others.

In both cases, coronaviruses were science new. Happily, both outbreaks were contained by incorporating human interference and still unexplained natural circumstances.

Coronaviruses became a household name worldwide in 2020. Most people have learned of extreme acute respiratory coronavirus-2 (SARS-CoV-2) or COVID-19.

Yet some may not know SARS-CoV-2 belongs to a virus family. And the family grows, we're afraid.

Scientists learn much about coronaviruses. Yet we don't know. So there's a possibility scientists neglected to detect a 19th-century coronavirus pandemic.

This brief introduction looks at the rising dynasty as well as the one we might have skipped that could teach scientists about COVID-19 and the human immune response.

Family relations

The International Virus Taxonomy Committee approved naming more than 40 coronaviruses. Many of these animals are infected.

The COVID-19 outbreak brought to seven the number of known coronaviruses infecting humans. Four of these have been obtained and spread in the human population for a long time.

The other three — SARS-CoV, MERS-CoV, and SARS-CoV-2—appear to have recently jumped into the human population. Sorry, these three result in high mortality rates.

Everything zoonotic coronaviruses. Beginning in animals, they may be transmitted to humans after mutation, recombination and adaptation.

Some animal coronaviruses cause long-term or recurrent enzootic infections: they infect animals at a specific site, or during a season. Such animal coronaviruses co-evolved and developed over a very long period with their reservoir host. Therefore, zoonotic coronaviruses usually do not cause symptoms in their reservoir host. Even though, symptoms are very mild.

However, the concern is that these extended periods of animal coronavirus infection – along with a high rate of recombination with other viruses and a high rate of mutation – increase the likelihood of a coronavirus mutant having the ability to jump to another host.

There is evidence that when an animal coronavirus reaches a new host, a new cycle of adaptation between the coronavirus and the new host greatly increases the frequency of the disease. It is believed – but not yet confirmed – that the new host will adapt enough to the virus after a very long period of adaptation and co-evolution to be able to fight it more effectively.

This would produce milder effects.

The seven human coronaviruses had domestic and wild mammals as intermediate and amplifying hosts. This suggests that they transformed into humans through a few other species, possibly originating in bats and rodents.

The four human coronaviruses acquired by the community—meaning they are acquired or present in the general population—typically cause mild, cold-like symptoms in humans.

Two of them, hCoV-OC43 and hCoV-229E, have accounted for 10-30% of all common colds since the 1960s.

While these coronaviruses cause infections year-round, increases in infections occur in the winter and early spring months.

Unlike other respiratory diseases, such as influenza virus, the causes are not completely clear. This group of human coronaviruses usually infects all ages; multiple reinfections are normal in human life.

One we might have missed

Biological sciences use molecular dating to measure the age of evolutionary events. Also used to investigate the roots of viral epidemics.

In 2005, a Belgian research group postulated that the ancestor of hCoV-OC43, one of the current human coronaviruses responsible for common cold, jumped from cattle to humans, leading to what they identified as

Scientists claim that a highly infectious respiratory disease with high mortality rates, now known as contagious bovine pleuropneumonia, affected cattle herds worldwide in the second half of the 19th century.

While most industrialized countries conducted major culling operations between 1870 and 1890 and were able to eradicate the disease by the early 20th century, it is possible that culling staff, animal handlers and farmers may have been exposed to coronavirus-infected bovine respiratory secretions.

A human outbreak due to influenza spread around the world at the same time as this cow-to-human coronavirus leap may have occurred. This 1889-1890 pandemic was characterized by a general sense of fatigue, pain, fever, and symptoms of the central nervous system.

A human outbreak due to influenza was occurring around the world at the same time as this cow-to-human coronavirus may have occurred. A general sense of weakness and pain, fatigue, and pronounced symptoms of the central nervous system characterized this 1889-1890 pandemic.

Over one million deaths were related to this pandemic. A substantial rise in fatality with that age was reported; this suggests that, as early COVID-19 results would indicate, the elderly were hit harder.

While modern science work related this outbreak to an H2N2 influenza virus, absolute proof was never obtained to link this flu virus to the outbreak.

This is primarily due to lack of tissue samples from that time.

And if the influenza virus wasn't responsible for the 1889-1890 pandemic, will there be another guilty? Since the most recent ancestor of bovine coronavirus and hCoV-O43 was both traced to around 1890, and hCoV-OC43 is now considered to have the ability to invade and assault the nervous system, could the pandemic of 1889-1890 have resulted from the jumping of cow coronavirus to humans?

If the answer is "yes," the next question is: does the 130-year pandemic adaptation and co-evolution justify why CoV-OC43 currently causes only moderate, cold-like symptoms in humans? How does the same virus that killed a million people in the 1890s now trigger only a few irritating sniffles?