A Look at the New Coronavirus

By Elva Chen (陳世慧)
Reviewed by Chen Hui-wen (陳慧文)
Abridged and translated by Chang Yu Ming (張佑民)
Syharn Shen (沈思含)

A Look at the New Coronavirus

By Elva Chen (陳世慧)
Reviewed by Chen Hui-wen (陳慧文)
Abridged and translated by
Chang Yu Ming (張佑民)
Syharn Shen (沈思含)

The COVID-19 outbreak, caused by a newly discovered coronavirus (SARS-CoV-2), is currently centered in China's Wuhan, resulting in high numbers of confirmed cases and deaths that collapsed the local healthcare system. In other places of the world, with a relatively low death rate of around 0.5%, COVID-19 has still managed to plunge the world into chaos, causing huge disruptions in many countries' healthcare system, economy, politics and society.

Vice president of the Republic of China (Taiwan) Chen Chien-jen (陳建仁), also a public health expert, suggested that COVID-19 may well become an infectious disease that appears periodically, like the common flu. So, instead of panicking, we should become familiar with it and understand it so we can face it without unnecessary worries.

The Family of Coronaviruses
Coronaviruses form a large family of viruses that cause diseases such as SARS (Severe Acute Respiratory Syndrome) which broke out in 2003, MERS (Middle East Respiratory Syndrome) in 2012, and the current COVID-19.

The earliest discovery of a coronavirus was found on chickens as reported by Beaudette and Hudson in the 1930s, while the finding of a coronavirus on humans did not emerge until the 1960s.

To date, coronaviruses can be categorized into 4 sub-groupings by their genetic similarities, and more than 16 types of the virus have been discovered. Both humans and animals, such as bats, pigs, cows, dogs, cats, rats and chickens, can be infected by coronaviruses.

In the case of COVID-19, bats are said to be the earliest carriers of the virus. With many species and vast numbers that amount to a quarter of all mammals, bats as one of the oldest animals on Earth have evolved a unique immune system that allows them to coexist in peace with most viruses.

However, other animals are not as lucky. Pigs infected with transmissible gastroenteritis virus (TGEV) suffer from diarrhea and vomiting. Cows infected with bovine coronavirus (BCoV) experience severe diarrhea. Cats can also be infected by feline coronavirus (FCoV), which can lead to intestinal infection and even feline infectious peritonitis, or inflammation of the abdomen's lining. Dogs can be infected by two coronaviruses, with one causing intestinal infection while the other resulting in respiratory infection.

Chen Hui-wen (陳慧文), an associate professor in the Department of Veterinary Medicine at National Taiwan University, said that coronaviruses found on animals can be divided into deadly and non-deadly ones. It is the same for coronaviruses found on humans as well. For example, coronaviruses can also cause the common cold, and through years of experience, we have learnt how to treat the mild illness. But when faced with a whole new coronavirus, we are still much in the dark.

Comparison Chart of Epidemics

(Source: Taiwan Centers for Disease Control)

The Jump from Animals to Humans
What is the purpose of the crown on the coronavirus? "Actually, the crown is a protein that the virus uses to infect cells," said Chen. After the virus enters our body and attaches itself to one of our cells, the crown serves like a "key" that unlocks the "gate" into our cell before the virus fuses its membrane with our cell membrane, resulting in an infected cell. Once inside the human cell, the virus releases its genetic material called RNA, which hijacks human ribosomes to start replicating viral RNAs.

A real problem of coronaviruses lies in their high mutability. For example, each strain of feline and avian coronaviruses is different. This is because when RNA viruses replicate, they have higher error rates, making them prone to mutations and jumps across species. This explains how the SARS virus started from bats, passed on to civets, and then onto humans. Similarly, the new coronavirus responsible for the current COVID-19 outbreak is said to have passed from bats to pangolins, and caught by humans in the process of catching and handling the animals.

"The genetic mutations of coronaviruses can be so fast that every one or two days can be a life cycle for them," added Chen. Furthermore, during each infection, the virus may undergo several mutations, so even in the same host, the virus may change into different strains.

Since coronaviruses and influenza viruses have RNA replications that may result in different mutations, what does that mean for us? "What we are worried about is, what if the virus starts to attack the kidney? Or the liver? The threat that viral mutations bring are the different ways that the host may be infected," Chen answered. That said, she also pointed out that luckily, not every mutation is in the virus's favor. As mutations are random, only better mutations keep the virus alive. Survival of the fittest, as they say. "For example, in the case of SARS, the virus killed its own host and consequently died as well. But for the new coronavirus, we can only wait and see how it plans to survive."

The Transmission of the New Coronavirus The world is still unable to determine the exact route of transmission for the new coronavirus that causes COVID-19. When the disease broke out in China's Wuhan in December 2019, a number of infected patients were reported to have visited the Huanan Seafood Market. Although the virus was found in some of the samples taken from the market, the source of the infection is still unable to be identified. Reports of infection among medical professionals and family members of infected patients strongly suggest that the virus has a high possibility of spreading among humans via direct or indirect contact with respiratory droplets of infected patients. Illustration by Chen Hui-wen's research team, Department of Veterinary Medicine, National Taiwan University.

Transmission During the Incubation Period
In any case, experts are certain that the new coronavirus can be transmitted between humans through respiratory droplets and contact with infected people (aerosol or feces are also said to be means of spread, though there is no official evidence yet). The COVID-19 virus is also much more contagious than the SARS virus.

The sharp rise in infected cases can mainly be attributed to the virus having mutated to allow spread from humans to humans, but another very likely cause is the spread of the virus by asymptomatic carriers, or people that have been infected but display no symptoms.

An expert in coronaviruses dubbed as "the father of coronavirus research" in Taiwan, former Academia Sinica vice president Michael M. C. Lai (賴明詔) stated that after the coronavirus enters the human body, only infected cells can produce new copies of the virus, which are transmitted to another person through coughing or sneezing. "When there is a viral infection, the body's immune system is triggered. This defensive mechanism not only fights the virus, but also causes fever and coughing as well. However, these symptoms only appear after the virus has reached a certain amount of replications inside the human body, and the period before the symptoms emerge is called the 'incubation period,'" Lai explained.

In the case of SARS, infected patients only spread the virus after symptoms like fever and cough appear. Yet, Ma Xiaowei (馬曉偉), minister of the National Health Commission of the People's Republic of China, announced in a press conference on January 26, 2020 that based on observation reports, the new coronavirus is contagious during the incubation period. Ho Mei-shang (何美鄉), researcher of the Institute of Biomedical Sciences at Academia Sinica, expressed that she is "almost certain" that asymptomatic carriers can also spread the virus. Her statement is another example strongly suggesting that the new coronavirus is super contagious.

The war between humans and viruses has been present ever since the beginning of time. Luckily, with the successful isolation of a second coronavirus strain in Taiwan made by a team at National Taiwan University's College of Medicine, Lai said that "the structure and function of the new coronavirus, in particular the characteristics of its spike proteins, have been fully understood. So, it is only a matter of time before a vaccine is developed."

Human beings and viruses used to evolve and develop in separate environments. It is, however, because of humans' unchecked greed, as shown in our over-exploitation of nature and relentless slaughtering of animals for food, that we have crossed the line and brought disasters upon ourselves. While we should still actively seek scientific and medical breakthroughs for a cure, the key to solving the crisis may lie in humbling ourselves and living in balance with nature. This may be the only way for us to coexist peacefully with viruses.

Ever since the COVID-19 outbreak started in December 2019, the world has spiraled into panic and chaos. By understanding the new coronavirus responsible for the disease, we may be more at ease and less distressed.

The COVID-19 outbreak, caused by a newly discovered coronavirus (SARS-CoV-2), is currently centered in China's Wuhan, resulting in high numbers of confirmed cases and deaths that collapsed the local healthcare system. In other places of the world, with a relatively low death rate of around 0.5%, COVID-19 has still managed to plunge the world into chaos, causing huge disruptions in many countries' healthcare system, economy, politics and society.

Vice president of the Republic of China (Taiwan) Chen Chien-jen (陳建仁), also a public health expert, suggested that COVID-19 may well become an infectious disease that appears periodically, like the common flu. So, instead of panicking, we should become familiar with it and understand it so we can face it without unnecessary worries.

The Family of Coronaviruses
Coronaviruses form a large family of viruses that cause diseases such as SARS (Severe Acute Respiratory Syndrome) which broke out in 2003, MERS (Middle East Respiratory Syndrome) in 2012, and the current COVID-19.

The earliest discovery of a coronavirus was found on chickens as reported by Beaudette and Hudson in the 1930s, while the finding of a coronavirus on humans did not emerge until the 1960s.

To date, coronaviruses can be categorized into 4 sub-groupings by their genetic similarities, and more than 16 types of the virus have been discovered. Both humans and animals, such as bats, pigs, cows, dogs, cats, rats and chickens, can be infected by coronaviruses.

In the case of COVID-19, bats are said to be the earliest carriers of the virus. With many species and vast numbers that amount to a quarter of all mammals, bats as one of the oldest animals on Earth have evolved a unique immune system that allows them to coexist in peace with most viruses.

However, other animals are not as lucky. Pigs infected with transmissible gastroenteritis virus (TGEV) suffer from diarrhea and vomiting. Cows infected with bovine coronavirus (BCoV) experience severe diarrhea. Cats can also be infected by feline coronavirus (FCoV), which can lead to intestinal infection and even feline infectious peritonitis, or inflammation of the abdomen's lining. Dogs can be infected by two coronaviruses, with one causing intestinal infection while the other resulting in respiratory infection.

Chen Hui-wen (陳慧文), an associate professor in the Department of Veterinary Medicine at National Taiwan University, said that coronaviruses found on animals can be divided into deadly and non-deadly ones. It is the same for coronaviruses found on humans as well. For example, coronaviruses can also cause the common cold, and through years of experience, we have learnt how to treat the mild illness. But when faced with a whole new coronavirus, we are still much in the dark.

Comparison Chart of Epidemics

(Source: Taiwan Centers for Disease Control)

The Jump from Animals to Humans
What is the purpose of the crown on the coronavirus? "Actually, the crown is a protein that the virus uses to infect cells," said Chen. After the virus enters our body and attaches itself to one of our cells, the crown serves like a "key" that unlocks the "gate" into our cell before the virus fuses its membrane with our cell membrane, resulting in an infected cell. Once inside the human cell, the virus releases its genetic material called RNA, which hijacks human ribosomes to start replicating viral RNAs.

A real problem of coronaviruses lies in their high mutability. For example, each strain of feline and avian coronaviruses is different. This is because when RNA viruses replicate, they have higher error rates, making them prone to mutations and jumps across species. This explains how the SARS virus started from bats, passed on to civets, and then onto humans. Similarly, the new coronavirus responsible for the current COVID-19 outbreak is said to have passed from bats to pangolins, and caught by humans in the process of catching and handling the animals.

"The genetic mutations of coronaviruses can be so fast that every one or two days can be a life cycle for them," added Chen. Furthermore, during each infection, the virus may undergo several mutations, so even in the same host, the virus may change into different strains.

Since coronaviruses and influenza viruses have RNA replications that may result in different mutations, what does that mean for us? "What we are worried about is, what if the virus starts to attack the kidney? Or the liver? The threat that viral mutations bring are the different ways that the host may be infected," Chen answered. That said, she also pointed out that luckily, not every mutation is in the virus's favor. As mutations are random, only better mutations keep the virus alive. Survival of the fittest, as they say. "For example, in the case of SARS, the virus killed its own host and consequently died as well. But for the new coronavirus, we can only wait and see how it plans to survive."

The Transmission of the New Coronavirus
The world is still unable to determine the exact route of transmission for the new coronavirus that causes COVID-19. When the disease broke out in China's Wuhan in December 2019, a number of infected patients were reported to have visited the Huanan Seafood Market. Although the virus was found in some of the samples taken from the market, the source of the infection is still unable to be identified.

Reports of infection among medical professionals and family members of infected patients strongly suggest that the virus has a high possibility of spreading among humans via direct or indirect contact with respiratory droplets of infected patients.

Illustration by Chen Hui-wen's research team, Department of Veterinary Medicine, National Taiwan University.

Transmission During the Incubation Period
In any case, experts are certain that the new coronavirus can be transmitted between humans through respiratory droplets and contact with infected people (aerosol or feces are also said to be means of spread, though there is no official evidence yet). The COVID-19 virus is also much more contagious than the SARS virus.

The sharp rise in infected cases can mainly be attributed to the virus having mutated to allow spread from humans to humans, but another very likely cause is the spread of the virus by asymptomatic carriers, or people that have been infected but display no symptoms.

An expert in coronaviruses dubbed as "the father of coronavirus research" in Taiwan, former Academia Sinica vice president Michael M. C. Lai (賴明詔) stated that after the coronavirus enters the human body, only infected cells can produce new copies of the virus, which are transmitted to another person through coughing or sneezing. "When there is a viral infection, the body's immune system is triggered. This defensive mechanism not only fights the virus, but also causes fever and coughing as well. However, these symptoms only appear after the virus has reached a certain amount of replications inside the human body, and the period before the symptoms emerge is called the 'incubation period,'" Lai explained.

In the case of SARS, infected patients only spread the virus after symptoms like fever and cough appear. Yet, Ma Xiaowei (馬曉偉), minister of the National Health Commission of the People's Republic of China, announced in a press conference on January 26, 2020 that based on observation reports, the new coronavirus is contagious during the incubation period. Ho Mei-shang (何美鄉), researcher of the Institute of Biomedical Sciences at Academia Sinica, expressed that she is "almost certain" that asymptomatic carriers can also spread the virus. Her statement is another example strongly suggesting that the new coronavirus is super contagious.

The war between humans and viruses has been present ever since the beginning of time. Luckily, with the successful isolation of a second coronavirus strain in Taiwan made by a team at National Taiwan University's College of Medicine, Lai said that "the structure and function of the new coronavirus, in particular the characteristics of its spike proteins, have been fully understood. So, it is only a matter of time before a vaccine is developed."

Human beings and viruses used to evolve and develop in separate environments. It is, however, because of humans' unchecked greed, as shown in our over-exploitation of nature and relentless slaughtering of animals for food, that we have crossed the line and brought disasters upon ourselves. While we should still actively seek scientific and medical breakthroughs for a cure, the key to solving the crisis may lie in humbling ourselves and living in balance with nature. This may be the only way for us to coexist peacefully with viruses.