Omi Kerong is getting closer and closer, what kind of demon can the new crown do?

Omiqueron has set off a "tsunami" of cases around the world, and in the first week of 2022, there were more than 7 million new confirmed cases of covid-19 in Europe. At the current rate of transmission, it is expected that in 6-8 weeks, more than half of Europeans may be infected with Omikeron. On January 10, the United States received more than 1.43 million infections on that day, the highest number of days in the world since the COVID-19 pandemic in a single country. Apparently, Omikeron is replacing Delta globally as the dominant strain.

At present, the domestic epidemic situation has spread in many places, and Omicron has been secretly spread to Tianjin, and then to Anyang, Henan and Dalian, Liaoning. At present, there are more than 200 indigenous infected people in these three places. Apparently, Omikeron was getting closer and closer to us.

However, WHO Director-General Tedros Adhanom Ghebreyesus is optimistic that if 70% of the world's population is vaccinated, the "acute phase" of the pandemic could end this year. So, after Aumeicron, how will this huge new crown epidemic end?

The British "Nature" recently published a long article discussing the future of the new crown epidemic. How the coronavirus evolves over the next period of time will determine how the global pandemic ends — whether it will turn into another common cold, or into the flu, or some other, more dangerous disease.

People line up to be tested for COVID-19 at a temporary testing center in New York City, USA, on Dec. 14, 2021. Brendan McDermid | Reuters

The "worst" possible ending

There has been a constant struggle between humans and pathogenic microbes. From this point of view, human history is a history of the struggle against disease.

A few days ago, Zhang Wenhong and others from Huashan Hospital affiliated to Fudan University wrote an article pointing out that "the game between viruses and humans like the new crown is believed not to start today." Such as seasonal influenza, seasonal coronavirus, etc., all retain traces of the human immune system fighting with pathogens in ancient times. The immune memory and immune barrier that remain in our bodies still play an important role for tens of thousands of years. ”

By observing past epidemics of infectious diseases, the future of virus evolution is predicted. In the article, Yuen Calaway, a senior reporter for the journal Nature, gave several possible future directions for the new crown virus. Among them, the most favorable, but also the most unlikely, outcome for the new crown virus is that the future, like the measles virus, has no immune escape ability but still exists.

Measles is one of the most contagious human diseases. The measles virus is transmitted through droplets of respiratory secretions, and a notable feature is that it is very contagious, and once in contact with an infected person, 90% of people without immunity will be "recruited"; another feature is that it is mainly transmitted in newborns, because a history of measles infection or vaccines can lead to lifelong immunity.

Before the advent of vaccines, measles was distributed worldwide and was one of the most serious infectious diseases that endangered the lives and health of children. According to the U.S. Centers for Disease Control and Prevention, in the 10 years before the vaccine was introduced, almost all children had measles before the age of 15. At that time, it was estimated that between 3 million and 4 million people in the United States were infected each year.

It is important to note that the measles virus is very poorly tolerant of mutations, with little immune evasion, and infection with the virus or measles vaccination can bring lifelong immunity.

"Zhuang Youcat", an excellent blogger on medical topics, once replied to netizens that the measles vaccine is a highly effective vaccine, with an effective rate of more than 97% in two doses, and the protective power can be maintained for decades. In the nearly 30 years from 1980 to 2009, China reduced the incidence of measles by 98% through vaccination, averting more than 100 million people and nearly a million deaths.

This means that as long as the measles vaccine is vaccinated in a timely and effective manner, the measles virus will have nowhere to hide. This is also one of the characteristics of the measles virus that clearly distinguishes it from RNA viruses such as influenza and new coronavirus.

In addition to being like the measles virus, the new coronavirus is more likely to evolve in the same direction as the respiratory syncytial virus.

Respiratory syncytial virus mainly causes lower respiratory tract infections such as bronchiolitis and pneumonia in infants under 6 months of age, as well as upper respiratory tract infections such as rhinitis and colds in older children and adults. Currently, there are no specific therapeutic agents or preventive vaccines for respiratory syncytial virus, but most cases are not serious.

Due to the combined effect of weakened immunity and virus evolution, new respiratory syncytial virus variants circulate every year around the world. Almost all children become infected in the first two years of life, most of the time with mild symptoms, similar to a cold, but can also cause serious illnesses such as pneumonia, bronchiolitis and other lower respiratory tract diseases.

According to the U.S. Centers for Disease Control and Prevention, 1-2 out of every 100 infected children under 6 months of age who are infected with respiratory syncytial virus require hospitalization.

Andrew Lambot, an evolutionary biologist at the University of Edinburgh in the United Kingdom, believes that if the new crown virus develops in this direction, coupled with a vaccine that can prevent severe diseases, "then it is likely to become a child virus".

However, Jin Dongyan, a virology expert at the University of Hong Kong, said in an interview with China News Weekly that "this is not in line with the characteristics of the new crown virus itself, and its future direction will not be similar to measles and respiratory syncytial viruses."

It's as long-lasting as the flu

At present, the "limelight" of the Omiljung variant is in full swing, but most of the confirmed cases that can be observed are mild. Some experts believe that this may be a turning point in the evolution of the new crown virus in the direction of influenza viruses, that is, it may cause large-scale transmission, but it will not be too deadly.

In fact, as early as February 2020, Wang Chen, vice president of the Chinese Academy of Engineering and an expert in respiratory and critical care medicine, proposed that the new crown virus may turn into a chronic, long-term disease like the flu in the human world, "this possibility is completely existent, and we must be prepared for this."

Before the COVID-19 outbreak, the worst pandemic in recent history was the influenza virus that broke out in 1918-1919. The flu virus infected about a third of the world's population (about 500 million people) at the time, killing 50 million people worldwide.

With no vaccines at the time, people were urged to quarantine, maintain good personal hygiene, and limit social interactions, which later proved effective. Two studies published in the Proceedings of the National Academy of Sciences in 2007 looked at the effects of more than 15 urban sanitation measures in 1918, including mask wearing, limiting business hours, and closing schools and theaters. Both studies found that the earliest and most aggressive cities had far lower mortality rates than others.

Influenza viruses are an ancient class of pathogens, but it wasn't until 1933 that the virus was first isolated. At present, influenza viruses are divided into A (A), B (B), C (C) three types, and the influenza viruses that have been discovered in recent years are classified as type D (D).

Because of the high mutation rate of influenza viruses, people need to get the flu vaccine every year. But even so, vaccines are only 40%-60% protective, and about 650,000 people die from influenza worldwide each year.

In the aforementioned Nature article, Youne Calaway speculated that another possible evolution direction of the new coronavirus is similar to the flu.

The article points out that influenza A viruses evolve rapidly and mutant strains can escape the immunity induced by previous strains, which makes seasonal influenza outbreaks occur every year around the world, sometimes in adults. Although influenza vaccines can reduce severe illness, influenza A viruses evolve too quickly, meaning that vaccines sometimes fail to keep up with new epidemic strains.

If the new coronavirus immune escape ability does not evolve quickly, it may be more similar to influenza type B virus. This means that its transmission mainly infects children, who are less immune than adults.

Trevor Bedford, a well-known American evolutionary virologist, believes that the final epidemic state of the new crown pneumonia epidemic will be similar to that of seasonal influenza. After considering factors such as virus evolution and vaccination, he believes that the new crown pneumonia will become a local infectious disease in the future, with about 20%-30% of people infected every year, and the case fatality rate is about 0.06%, which is similar to seasonal influenza.

In September 2021, Trevor Bedford and his team found that the coronavirus evolved much faster than the seasonal coronavirus, even faster than the influenza A virus. He expects the mutation of the coronavirus to eventually slow down to a more stable state, but "whether it needs to be renewed every two years, or every five years, like the flu A virus H3N2, or worse, is uncertain."

Sun Jiayi, a postdoctoral researcher at Cornell University School of Medicine, told China News Weekly that at present, the new crown virus is not as fast as the mutation speed of the influenza virus, "mainly depending on the mutation rate of the new crown virus, the future does not rule out the possibility of becoming more and more similar to the influenza virus."

"COVID-19 is no worse than seasonal flu." Robert Pearl, a clinical professor at Stanford University School of Medicine in the United States, recently wrote an analysis in the Seattle Times that by increasing the combination of vaccination, injection of reinforced injections and new antiviral treatment, the possibility of dying from new crown pneumonia will be 90%-95% lower than that of the beginning of 2020. From this, the possible mortality rate is between 0.05% and 0.1%, which is similar to the mortality rate of influenza infection in the United States.

He also pointed out that COVID-19 will not be exactly like the flu during a pandemic. For example, COVID-19 cases don't disappear completely every summer and then reappear like the flu in the following winter. On the contrary, this change is more locally controllable. However, in terms of risk, the two diseases are comparable.

The fifth seasonal coronavirus?

The emergence of Omikeron means that the new coronavirus is still evolving and is constantly adapting to the humans infected by it. Against the backdrop of increasing numbers of vaccinations and infections, the coronavirus must evolve in order to continue to be contagious.

A growing body of research suggests that the Omikejong variant appears to be infected primarily in the upper respiratory tract and causes milder symptoms than previous strains, which primarily cause severe lower respiratory tract and lung infections. French virologist Bruno Linner analyzed that the direction of the evolution of the new crown virus has undergone some kind of change, which may indicate that the new crown virus has begun to shift in a less serious and more conventional direction.

Among them, studies from South Africa and the United Kingdom have shown that people infected with Omicron are less ill compared to those infected with Delta, and the rate of severe illness and mortality are decreasing. When doctors in South Africa first discovered Omi kerong, they observed that the patient's symptoms were more like colds than flu.

Therefore, there is an argument that Omilon may be a "natural vaccine" that boosts immunity without causing serious disease.

As early as 2020, evolutionary biologist Jesse Bloom predicted that the new coronavirus will not be eradicated, but is likely to become the fifth coronavirus that can live forever in the human body - the other four coronaviruses 229E, HKU1, OC43, NL63 have been circulating in the population for at least several decades, but they cause mild symptoms.

In 2020, a study from the university medical center team in Amsterdam, the Netherlands, found that all 4 seasonal coronaviruses, with frequent re-infections, suggested that this may be a common feature of all human coronaviruses, including the new coronavirus.

Of the 4 coronaviruses, the most thoroughly studied is 229E, which can make infected people re-infected. However, it is unclear whether the cause of re-infection is due to a weakened human host immune response or because the virus can achieve immune escape through mutation.

By examining a batch of blood samples stored in the 1980s that had been infected with 229E, Jesse Bloom found that the 1980s blood samples contained a large number of antibodies against the 1984 229E variant, but the ability of these blood samples to neutralize the 1990s, 2000s and 2010s variants gradually weakened, and the same trend was seen in the 1990s. This suggests that the 229E virus has been evolving immune escape capabilities.

"Judging from the rapid rise of Omikejong in South Africa, it has mastered the trick of escaping human immunity." According to Jesse Bloom's analysis, the similarity between it and 229E is obvious from the evolution of the new crown virus in the past two years.

Jin Dongyan, a virology expert at the University of Hong Kong, pointed out that from the perspective of virus traceability, NL63 and 229E are from bats, while OC43 and HKU1 may be from rodents, but now these 4 viruses are common in humans and only cause the common cold. If you go back a few decades, a hundred or two hundred years or more, when these viruses first entered the human body, they also caused a global pandemic, similar to the current situation of the new crown virus.

Tom Winsells, an evolutionary biologist at the University of Leuven in Belgium, and other researchers have speculated that Omiljung's success may be largely due to its ability to infect people who have been vaccinated or have been immune to Delta with previous infections.

This evolutionary path from increasing infectivity to immune escape is common in existing respiratory viruses such as influenza viruses, and Adam Kuczynski, a mathematical epidemiologist at the School of Hygiene and Tropical Medicine in London, Uk Kingdom, believes that the simplest way for the new coronavirus to cause a new round of outbreaks is to gradually achieve immune escape, similar to seasonal coronaviruses.

Destiny is still in human hands

Although the current war between mankind and the new crown virus has not yet been won or lost, the initiative still seems to be in the hands of mankind.

"The mutation of the virus and the stability of the virus after the mutation are worth paying attention to." Wang Chen recently said that the new crown virus is very smart, it knows how to survive and adapt to itself. Its way of survival and adaptation must be increased transmissibility, reduced pathogenicity, and longer survival time in the body, which is the direction of its evolution.

Wang Chen pointed out that because there are too many variables in all aspects and uncontrollable, the direction of virus development has countless possibilities, it is difficult to predict, and it is difficult to have a "prophet" in really accurate time.

"The combination is highly contagious and toxic, and it's not a good deal for COVID-19." Jin Dongyan said that the overall variation is not large, the (toxicity) is getting weaker and weaker, and the spread is increasing, which is the evolutionary characteristics of the new crown virus. In the future, when it reaches a relatively stable state, it will not be able to change any tricks.

He stressed that "the 'change' of the new crown virus is not unlimited, and it will be limited by many specific conditions. "There are certain laws to follow in the evolution of the virus, because it eventually reaches a state of equilibrium. However, the specific length of this time is still impossible to determine.

Eun Calaway also gives other possibilities in the aforementioned Nature article. A document prepared by a group of scientific advisers from the Uk government suggests that the coronavirus could recombine with other coronaviruses, become more dangerous, and even invalidate the current vaccine. At the same time, continued transmission in animal hosts also increases the likelihood of unexpected mutations, such as those that can immune escape or become more pathogenic.

There is no doubt that human actions have played a non-negligible role in the fight against the new crown virus, including non-medical protective measures such as mass vaccination, insistence on wearing masks, and social distancing. According to the latest statistics of the data website "Our World in Data", as of January 11, 59.2% of the world's population has received at least one dose of the new crown vaccine, and 9.49 billion doses of vaccine have been received globally, and 35.22 million doses are currently given every day.

Jin Dongyan reminded that many people ignore that at this stage, the cumulative number of vaccine doses vaccinated in the world has reached an unprecedented scale, and such a large-scale vaccine coverage will inevitably change the evolutionary process of the new crown virus. Omikeron is a less pathogenic strain that evolved on the basis of mass vaccination and a large number of naturally infected people, and its transmission is particularly active in people who have been vaccinated or infected.

The evolution of the new crown virus will be in line with the past human coronavirus evolution path, but also have its own characteristics. Jin Dongyan analyzed that although large-scale human intervention has changed the evolution of the virus, in the long run, the evolutionary trend of the new crown virus is still gradually weakening.

Zhang Wenhong and others also said in a recent article that the emergence of Aomi Kerong reveals the law of the evolution of the new crown virus. Although it is not yet possible to fully judge the evolutionary outcome of this virus, whether it is more like measles chickenpox, or more like the common coronavirus such as 229E, or more like the flu, it now seems to be a self-contained way.

The current preliminary data suggest that the key node may lie in the extent to which the vaccine's booster vaccination strategy will be balanced with viral variants, which will determine the future outcomes of the disease's evolution in human society.

"The Omiljung mutation may not yet be the end of the evolution of the virus, and what form it will eventually survive is not yet known, and it may be that as Andrew Lambot, an evolutionary biologist at the University of Edinburgh in the United Kingdom, said, the new crown virus may not be decided yet." Zhang Wenhong wrote that at present, it seems that at least for now, fate is still in the hands of mankind.