Stanford University Scientists: Give up illusions and learn to coexist with the new crown

Faroe Islands

In the spring of 1846, the Dutch physiologist Peter Ludwig Panum came to the Faroe Islands between the Norwegian Sea and the North Atlantic to do research

Dutch physiologist Peter Ludwig Panum (Image source: Saddhiyama, Public domain, via Wikimedia Commons)

However, the average life expectancy of these residents was not low at that time, and they could live to 45 years old, which was comparable to or even slightly better than the neighboring big country Denmark

However, a measles outbreak suddenly occurred in the Faroe Islands

This trend changed suddenly at the age of 65

Peter's research points to an important fact: our bodies have memories

Coronavirus

However, the world is not as simple as we imagined

As early as 1990, a study explained this ruthlessly

A variety of coronaviruses can infect humans, and there is the possibility of repeated infections (Image source: CDC/ Dr.

　　But one thing is fortunate

　　This may indicate the future of the new crown virus

　　For this virus, we will not use isolation or home strategies to deal with it

　　The ability to coexist with the new coronavirus depends on the answers to a series of questions: How strong can our immune memory be? How will immunity decline in the face of the new crown variants? Unfortunately, it may take us many years to arrive at a clear conclusion

　　Antibody Experiment

　　On May 13, 2020, a fishing boat fishing for cod set sail from Seattle

　　In the vast ocean, a fishing boat is like an isolated island

　　In fact, antibodies are not the body's first line of defense against pathogens

　　The accident on the fishing boat shows that the new crown infection can prevent secondary infections at least for a period of time

　　Antibodies are indeed effective against diseases such as measles or smallpox, and can maintain immunity for decades
.
This is exactly what Peter observed on the Faroe Islands
.

　　But for other diseases, the effect of antibodies does not seem to be so lasting
.
For example, a 2007 study pointed out that employees working at the Primate Research Center in Oregon often produce antibodies against animal diseases in their bodies
.
Every 10-12 years, the level of these antibodies will be halved
.

Antibodies do not always bring protection (Image source: 123RF)

　　In the long run, how long will the level of antibodies against the new coronavirus suddenly fall off? It is still difficult to judge
.
However, from the perspective of SARS and MERS viruses, antibody levels will drop significantly after 2-3 years
.
Over time, the level of antibodies against the new coronavirus may also gradually decline
.

　　Of course, the decline in the level does not mean that the protective power will disappear
.
Of the three seafarers who tested positive for antibodies in Seattle, two had very low antibody levels, but they were sufficient to avoid secondary infections by the new coronavirus
.

　　Beyond the antibody

　　It should be pointed out that the immune system of our body is not only antibodies
.
"There are a series of memory cells in the human body waiting to be reactivated
.
" said Professor Marion Pepper, an immunologist at the University of Washington
.
In addition to B cells that produce antibodies, this also includes T cells that can destroy infected cells
.
They can be maintained at a very low level in the blood, but when the same pathogen is seen again, they can react in just 2-4 hours
.

　　Last summer, Professor Pepper's research group did a study on immunity
.
They recruited 15 volunteers who had a mild infection 3 months ago and looked for traces of antibodies, memory B cells, and memory T cells in their bodies
.
Finding these memory cells can be called a needle in a haystack, not to mention that these volunteers only had a mild infection, but the researchers still managed to find the cells they were looking for
.
"This gives me confidence in the immune system
.
" Professor Pepper added
.

WuXi AppTec content team mapping

　　But on the other hand, the virus will not wait in front of the immune system
.
As they accumulate mutations, the virus will become increasingly difficult to identify
.
In this "New Yorker" article, the author pointed out that the 1918 pandemic flu survivors had a strong immune response that was sufficient to target the same influenza virus
.
However, they still re-infect the flu every 5 years or so, because the mutation rate of the flu virus is so fast, almost every year it is a new variant, enough to escape the monitoring of T cells
.

　　What about the new coronavirus? From the perspective of other coronaviruses, the situation is not optimistic
.
From blood samples collected in the 1980s and 1990s, researchers found that antibodies against seasonal coronaviruses were not enough to identify new variants of these coronaviruses
.
Although the mutation rate of coronaviruses is slower than that of influenza viruses, they will still accumulate enough mutations over time to produce immune escape
.

　　New crown variants

　　Today, many variants of the new crown have broken into our world
.
Compared with the virus that first appeared, these variants are more transmissible and perhaps more lethal
.
Whether through infection or vaccine, the ability of antibodies generated earlier to bind to the virus has also declined, providing opportunities for repeated infections
.

　　The city of Manaus in Brazil is a typical example
.
In early 2020, the new crown virus has already raged in the area
.
Test results in October also showed that half of the city’s residents have the new coronavirus antibody, so that scientists believe that the area has reached the level of herd immunity
.
But in December, the city suffered a second wave of the new crown epidemic, and the situation was more severe than the first wave, bringing a large number of hospitalizations and deaths
.

The city of Manaus in Brazil made us realize the horror of the new crown variant (Image source: CIAT, CC BY-SA2.
0, via WikimediaCommons)

　　Some people attribute the tragedy to loose management, while others believe that previous studies have overestimated the immune level of the group
.
But the indisputable fact is that the Gamma variant found locally should at least bear some responsibility-this virus variant can greatly reduce the effectiveness of the antibody
.
A preprinted study that has not been peer-reviewed indicates that approximately one in six patients has a repeat infection
.

　　In the past few weeks, the Delta variant has caused even greater panic
.
However, the author of this article pointed out that no matter how the new crown variant changes, it still has similarities with the original virus
.
"Very few mutations can completely destroy the ability of antibodies to recognize a virus
.
" said Professor Scott Hensley, an immunologist at the University of Pennsylvania
.
Consistent with this judgment, current research still shows that vaccines developed by many companies can still maintain protection against the new coronavirus variant-mutations may reduce the binding ability of some antibodies, but other antibodies can remain unaffected
.
In addition, because T cells can recognize that they come from within the virus, not just the external protein fragments that are prone to mutations, the immunity it brings is still long-lasting
.

　　At present, the key to fighting the epidemic lies in accelerating the speed of global vaccination
.
The more people infected, the more chances of mutations are left for the virus
.
Past experience shows that no matter where the new variants are produced in the world, they can quickly sweep the world
.

　　The pandemic will only end if everyone is no longer infected
.

　　Resistance

　　Dr.
Katherine S.
Xue wrote in this in-depth report that a better term for immunity in disease is actually "resistance
.
" This shows that our body resists viruses and reduces the ability of infection to occur
.
Whether it is a vaccine or a previous infection, it helps us build up such resistance
.
The stronger our resistance, the higher the concentration of the virus we can tolerate, and thus our health
.

The author of this article, Dr.
Katherine S.
Xue (Image source: Dr.
Katherine S.
Xue’s official website)

　　The "resistance" perspective allows us to better examine the re-infection of the new crown
.
The world's first known second infection occurred in August last year.
After flying from Spain to Hong Kong, a man tested positive for the new crown
.
However, 5 months ago, he had just contracted the new coronavirus
.

　　After analysis, it was found that the symptoms of his first infection only appeared for a few days
.
And for some unknown reason, after the infection, the presence of antibodies could not be detected in his body
.
Even so, his second infection was an asymptomatic infection, and the virus could not be detected within a week
.

　　"This is a classic textbook case that tells us how the immune system works," said Professor Akiko Iwasaki, an immunologist at Yale University.
"When the immune system is not enough to prevent secondary infections, it can still prevent people from getting sick
.
" Maybe this name The patient's antibody level failed to prevent the virus from invading, but other immune functions kept the impact of the infection to a minimum
.

　　After the first case appeared, researchers also began to quantify the secondary infection of the new crown
.
Just like the story on the Seattle fishing boat, the facts have proved that the secondary infection rate is very low
.
Studies from Denmark and the United Kingdom have found that a few months after the new crown is positive, the chance of an adult being infected with the virus is 80% lower
.
Even if secondary infections do occur, they are mostly asymptomatic or mild infections
.

"Vaccine breakthrough cases" after vaccination are also uncommon (Image source: 123RF)

　　The same situation can happen to individuals who have been vaccinated but become infected
.
We call this kind of case a "vaccine breakthrough case"
.
Like secondary infections, "vaccine breakthrough cases" are not common and are more asymptomatic or mild infections
.
Data shows that in the first four months of 2021, millions of Americans have been fully vaccinated against the new crown
.
By the end of April, about 10,000 people were infected with the new crown virus, and only 1,000 were hospitalized
.
In terms of conversion, it means that only one of the hundreds of thousands of people who have been vaccinated is hospitalized
.

　　Currently, about a quarter of "vaccine breakthrough cases" are asymptomatic infections
.
This number may be underestimated, because many vaccinated individuals, even if they are infected with the new coronavirus, may not even notice
.

　　Learn to coexist

　　At the end of this article, the author points out that although the current vaccine has achieved great success, it is unlikely to completely eradicate the new coronavirus or to achieve herd immunity, because the spread of the virus has been too widespread and the virus still has Certainly spread
.

　　But in the long run, our relationship with the virus will undergo fundamental changes
.
More than a year ago, we were like residents of the Faroe Islands, with little ability to fight back against the new virus
.
And as the immune resistance of our group begins to grow, the new coronavirus will turn from a global pandemic to a local epidemic threat-the virus will continue to spread at a low level, but the spread will be slower, and the number of infected cases will not be as good as before.
Serious
.

　　The virus will mainly infect children who have not been vaccinated, but there is information that they will mainly have asymptomatic infections and hardly become severely ill
.
The virus also occasionally infects vaccinated adults, and the elderly or individuals with impaired immunity are also high-risk groups
.
There will still be people dying because of the new crown, but this situation will be the same as dying from flu and pneumonia
.
For most individuals with immune resistance, the risk of COVID-19 will continue to decline until it becomes a familiar part of our lives, like the flu
.

　　Historically, such an outcome is not unexpected
.
Since the 20th century, there have been four large-scale influenza epidemics.
Behind each epidemic is an influenza virus that can continue to spread for decades
.
Scientists speculate that the common cold virus today may also come from a pandemic in the past
.

　　In a world coexisting with the new crown, we are just like responding to the flu virus.
We will be vaccinated with booster shots every year, but there is still the possibility of infection
.
In the future, there may be a "new crown season" like the flu season, and a new variant will be produced every few years, and the variant in a certain year is particularly bad
.
We may get the new crown every few years.
In most cases, the symptoms are extremely mild, just like a cold
.
These occasional infections can enhance your immune resistance
.

　　Sometimes these infections can become serious
.
This may be because you did not receive a new vaccine that year, or the new variant virus is more harmful
.
Regardless of the reason behind it, this infection may leave you in bed for several weeks
.
When you get old and your immune system declines, the chance of complications will rise, just like the flu will bring you
.
If your resistance has dropped significantly, you should carefully consider your plan to travel in the new crown season
.

　　All in all, we hope that the new crown virus will only be a term in history, but it may eventually coexist with us
.
For a virus that changes frequently, our body does not respond perfectly
.
But at least, our brain knows how to respond
.