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Affected by the severe epidemic, a hospital in London, England launched a "disaster response model"

The virus has changed and changed, unexpectedly?

by YCPress

British Prime Minister Johnson announced on the 19th that a mutant novel coronavirus is spreading in London and southeastern England, spreading 70% faster than the original discovery of the virus.

This news immediately attracted wide international attention. Since the 20th, the level of COVID-19 prevention and control in London, southeastern and parts of eastern England has been upgraded from level 3 to the newly added level 4. So far, many countries have successively launched different entry restrictions on the UK.

On December 23, trucks lined up in Manston after France announced the lifting of restrictions on Britain due to the epidemic.

On the 23rd, British Health Secretary Matthew Hancock said that following the aforementioned discovery of one mutant novel coronavirus, another mutant novel coronavirus was discovered in the UK.

Is the mutation of COVID-19 dangerous? Can the existing vaccine be prevented? How to do a good job in prevention and control in the future? A series of questions are ahead.

“This is the normal part of the evolution of the virus”

On the 19th, it was announced that the mutant coronavirus that appeared in the UK was named “VUI-202012/01”. The UK found that the two earliest viral variants came from Kent and Greater London on September 20 and 21, respectively.

COVID-19 infects the human body by binding an S spiny protein on the surface of the virus to the ACE2 protein that controls blood pressure, thus invading the human body.

It was announced on the 19th that the COVID-19 mutation site in the United Kingdom is a key amino acid N501Y mutation in the S spinoprotein receptor binding region (RBD), which enhances susceptibility.

Visually speaking, one of the fingers (RBD) of the hand (S protein) of the novel coronavirus can open the fingerprint lock (ACE2) of the cell. Now that the finger (RBD) has mutated, it is easier to open the fingerprint lock (ACE2) of the cell.

In a sense, the mutation of COVID-19 is “expected”. For example, in the early stage of the epidemic, the world’s most important strain of COVID-19 was called strain D. However, the virus quickly mutated—the 614th amino acid on its spinoprotein changed from aspartic acid (D) to glycine (G). Studies have found that the virus, known as D614G mutation, has stronger adaptability.

The mutant virus was identified as early as February this year, when it was mainly spread in Europe and the Americas. Since then, mutant COVID-19 has also been found in South Africa, Spain, Denmark, Sweden, Malaysia and other countries and regions.

Some scientists have also done forward-looking research on the part of the coronavirus mutation announced in the United Kingdom on the 19th. In July this year, experts from the Institute of Microbiology and Epidemiology of the Chinese Academy of Military Medical Sciences and Fudan University jointly published a paper in Science, which mentioned that deep sequencing revealed that the N501Y mutation may be an adaptive mutation related to increased virulence.

The COVID-19 adapts and infects wild mice precisely because of this N501Y mutation. This mutation greatly increases the affinity between RBD and the receptor ACE2, making the COVID-19 strain that was not infected with mice capable of infecting mice.

Expert analysis believes that compared with previous COVID-19 mutations, the reason why the mutation announced on the 19th caused public panic is that the mutant virus spreads extremely fast.

According to the mathematical model of relevant British departments, the transmission rate of mutant COVID-19 has increased by 70%. Judging from the current dissemination situation, the actual situation is basically consistent with the deduction conclusion. For example, signs of increased transmission of mutant COVID-19 can be seen in the population.

In November, about one-fourth of the confirmed cases in London were infected with new strains of the virus, and the proportion rose to about two-thirds in mid-December.

Pei Jianfeng, a special researcher at the Frontier Interdisciplinary Research Institute of Peking University, told reporters that the mutation produced by the virus gene is a random mutation, which may produce a genetic mutation with strong infectivity.

The virus with this mutation will gain an evolutionary advantage, so it is normal to produce a highly infectious virus strain.

There is also a view that the coronavirus mutation announced on the 19th in the United Kingdom may be caused by the selective pressure caused by clinical medical countermeasures, which has also been previously shown that the choice pressure will lead to an accelerated evolution of the novel coronavirus.” It is also possible.

The pressure of choice is like biological evolution. Each creature has to gradually adapt to the environment in a special environment, which is natural selection. To survive, viruses need to constantly mutate and become adaptable to drugs.

The surviving virus can adapt to the external environment and can continue to pass on from generation to generation, and its descendants have this characteristic. An expert told the reporter.

“It’s important to be transparent and to tell the public the truth about things, but it’s also important to let the public understand that this is the normal part of the virus’s evolution,” Michael Ryan, the head of the World Health Organization’s emergency program, said in an online briefing.

A woman wearing a mask stands on the streets of London, England, with an umbrella on December 21. Photo by Han Yan

How long will the vaccine last for mutant viruses?

Vaccines are regarded as an important means to effectively control and even end the epidemic globally. But for the mutant coronavirus, the public has doubts about the effectiveness of existing vaccines.

In this regard, researchers in many countries agree that the mutation of COVID-19 has not affected the effect of vaccination for the time being.

Experts analyzed that not all viral mutations affect the effectiveness of vaccines, and some mutations do not affect.

“There have been multiple mutations in the past few months, some of which have driven the spread of the novel coronavirus, but there is currently no variant that can cause more serious illness or escape diagnosis, nor does it affect vaccine effectiveness,” Michael Ryan said.

In fact, there is no evidence that the mutant virus announced in the United Kingdom on the 19th affects the effectiveness of the vaccine.

The aforementioned paper published by experts from the Chinese Academy of Military Medical Sciences and others shows that strains with N501Y mutations can still be neutralized by COVID-19 RBD-specific neutralizing antibodies.

At present, the situation is optimistic, but some experts remind that now we can only speculate whether the vaccine is useful or not, and we need to use clinical trials to prove that the mutation virus is tested to see whether the antibodies induced by the vaccine are still effective against the mutant virus.

Zeng Guang, a former chief epidemiologist of the Chinese Center for Disease Control and Prevention, believes that from scientific theory, the current mutant virus will not affect the effect of the vaccine.

The vaccine should be effective, but further research is needed.

At present, many pharmaceutical companies have tested the efficacy of vaccines against mutant COVID-19. Modner said it predicted that its vaccine would immunize people against mutant coronavirus.

The company will carry out more tests in the next few weeks to confirm this expectation. Pfizer Pharmaceuticals said that the relevant data is being generated, and it is studying blood samples from people who have been immunized with its vaccine to determine the extent to which the vaccine can invalidate the mutant coronavirus.

The CEO of German biotechnology said that the company is testing whether the vaccine it has developed jointly with Pfizer Pharmaceuticals is effective against mutant COVID-19, and is expected to reach a conclusion within the next two weeks.

“The vaccine designed in China is based on early isolated strains.

It is recommended that the country speed up testing to see if the existing vaccines are still very protective against emerging mutant viruses and whether the existing antibodies can remain highly active against new mutant viruses.” Zhong Wu, a researcher at the National Drug Engineering Technology Research Center for Emergency Prevention and Control, told reporters.

As for when the virus may mutate into vaccine-immune strains, Zhang Wenhong, director of the Department of Infectious Diseases of Huashan Hospital Affiliated to Fudan University, believes that there can be no evolution of the virus without natural selection.

Similarly, without the pressure of vaccines, it is basically impossible to naturally screen out viral mutation strains that are invalid for vaccines.

The mutant strain announced on the 19th first appeared in September, much earlier than vaccination, and it is unlikely that there will be a mutation that is invalid for the vaccine. Vaccines that have proved effective in trials so far can only be screened out mutations that are ineffective to the vaccine due to vaccine pressure after it is on the market.

A nurse was vaccinated against the coronavirus in Augusta, Georgia, United States on December 22.

What does the second stage of prevention and control rely on?

Experts believe that from the reporting of the COVID-19 epidemic to the successful development of a vaccine, people can only fight the virus by controlling social distancing.

The vaccine has been successfully developed, and the global epidemic has entered the second stage.

Zeng Guang believes that European and American countries have entered the second stage of infection at a high level.

Although China is at a low level, in winter, the epidemic also shows a trend of multi-point occurrence and frequency acceleration, and it is still necessary to wait to do a good job in the prevention and control of the second phase of the COVID-19 epidemic. COVID-19 is the enemy we fear, and it can take advantage of all the loopholes.”

On the basis of traditional means, experts suggest that vaccination should be done. Wang Huaqing, chief expert of immunization planning at the Chinese Center for Disease Control and Prevention, said that after the first step of immunization for key populations, it will be expanded to other populations in the future. When the vaccination rate in the population reaches a very high level, the immune barrier can be established.

Earlier studies have shown that the population immunity threshold can block the spread of COVID-19 at about 70%.” We look forward to the day when the epidemic will be able to end the disease through immune prevention measures, or control it at very small intensity, with only some spreads.

Pei Jianfeng also believes that vaccination of a certain proportion of the population can slow down the spread of the virus.” Some people may be skeptical about the safety of the vaccine, but I will personally go to the vaccine, because the current emergency vaccine and upcoming vaccines in our country are inactivated vaccines, which have been verified for a long time and are very safe.

Judging from the emergency vaccination of COVID-19 inactivated vaccine in China, the vaccine has high safety.

The reporter learned that China has approved the emergency use of the novel coronavirus vaccine in accordance with the law and regulations since June. Since July, more than 1 million doses of the COVID-19 vaccine have been carried out.

Zheng Zhongwei, head of the special working group of vaccine research and development of the scientific research and control group of the Joint Prevention and Control Mechanism of the State Council and director of the Medical and Health Science and Technology Development Research Center of the National Health Commission, said: “After our strict adverse reaction monitoring and tracking and observation, there are no serious adverse reactions in the participants at present.

More than 60,000 of them went to high-risk areas abroad, and no serious cases of infection have been reported.

The reporter learned from Chinese medicine Zhongsheng and Beijing Kexing that the domestic listing of three inactivated vaccines of these two companies is steadily advancing.

In addition, from foreign situations, on December 9, the Ministry of Health and Prevention of the United Arab Emirates said in a statement that according to the relevant application, the United Arab Emirates officially registered the inactivated coronavirus vaccine developed by China National Pharmaceutical Group, which is a major vote of confidence in the UAE government on the safety and effectiveness of the vaccine.

On December 23, the government of São Paulo and the Butan Institute announced that the Kelifou coronavirus vaccine developed by Beijing Kexing Zhongwei Biotechnology Co., Ltd. was effective, and further analysis of the test results will be completed in 15 days. Turkish Health Minister Koja said on the 24th that the results of the vaccine test in Kexing, Beijing, showed that the vaccine was safe and effective.

Will it impact next year’s economy?

The variant nature of the virus is like a time bomb, filling the uncertainty of the upcoming 2021. There is a fear that if the mutant coronavirus spreads globally, it will take another wave of shocks to the global economy.

Zhang Monan, an associate researcher in the World Economic Research Office of the Economic Forecasting Department of the National Information Center, told reporters: “If the mutant coronavirus outbreak occurs in a large scale around the world, countries may take blockade measures.

Such a large blockade may lead to the chain of the supply chain of the industrial chain.”

Zhang Moman analyzed that the limited international exchanges under the impact of the epidemic will directly lead to the shutdown of international trade.

If the novel coronavirus spreads on a large scale, the situation facing countries around the world will be more severe than at the beginning of the year.

Due to the high infectivity of mutant COVID-19, many countries may adopt measures such as import and export restrictions and complete border closure, which will have an impact on the industrial chain and supply chain.

Judging from the reactions of previous countries, Zhang Monan believes that the impact of the epidemic may aggravate the deep recession of the world economy, lead to a sharp contraction of international trade and investment, and trigger turbulence in international financial markets.

Some countries may also adopt more radical trade protectionist measures.

In the impact of the COVID-19 epidemic on China’s economic and social development at the beginning of the year, the success of the digital economy has become a strong driving force for China’s economic growth.

Zhang Moman suggested to develop the digital economy with a more encouraging innovation, inclusive and prudent manner, such as increasing the export of high- intellectual property value-added products, developing a new generation of digital technologies such as AI, and reasonably coordinating and taking into account the interests of the state, consumers and enterprises.

“The new technology revolution is a big wave to wash sand.

We should make full use of the COVID-19 crisis and not be blocked by the crisis.” Zhang Monan said.

Anti-variability, can a vaccine work?

Entering December, the nearly year-long COVID-19 vaccine research and development competition has achieved positive results, and many countries have begun to lay out vaccination.

At present, under the guidance of the “two-step” vaccination strategy in China, many cities in Guangdong, Sichuan, Henan and other places have successively carried out COVID-19 vaccination work for key populations.

How effective is the long-awaited coronavirus vaccine? Under the new situation of accelerating the spread of the epidemic abroad and even the mutation of the novel coronavirus, will the current COVID-19 vaccine be largely ineffective? What impact will the prevention and control of the epidemic in China be affected?

Don’t worry, come and see.

“Two Steps” to Establish an Immune Barrier

It has become a global consensus to achieve herd immunization through large-scale vaccination and thus control the COVID-19 epidemic.

On December 22, an old man was vaccinated against the novel coronavirus at the coronavirus vaccination center in Tel Aviv, Israel. Photo/Xinhua News Agency

In some European and American countries with severe epidemics, the need for vaccination seems to be more urgent. On December 8, the United Kingdom began mass vaccination against the novel coronavirus.

On the same day, Margaret Keenan, 90, became the first person to be vaccinated against the novel coronavirus in the United States and Canada.

On December 14, the first round of vaccination began, with front-line medical staff. Israel launched the coronavirus vaccine on December 20. Inoculation work, first of all, inoculation for medical personnel, people over 60 years old, severe and chronically ill patients, etc.

Compared with European and American countries, the overall situation of COVID-19 prevention and control in China is good.

However, Wang Huaqing, chief expert of immunization planning at the Chinese Center for Disease Control and Prevention, believes that the current global prevention and control situation is still very severe. The vast majority of people in China are susceptible to COVID-19. In this case, vaccination is very necessary.

On December 19, China announced the “two-step” vaccination strategy and officially launched the COVID-19 vaccination work for key populations.

Cui Gang, head of the Disease Control and Control Bureau of the National Health Commission, said that the first step of the “two-step” is mainly to carry out vaccination for some key populations, including workers engaged in imported cold chain, port quarantine, ship pilotage, aviation air service, fresh market, public transportation, medical disease control and other workers with high risk of infection.

Personnel, as well as personnel who go to medium- and high-risk countries or regions to work or study, try their best to relieve the pressure of imported epidemic prevention and control, and reduce the risk of local cases and domestic outbreaks.

The second step is that with the conditional approval of vaccines or the gradual increase of vaccine production, more vaccines will be put into use.

Through the orderly vaccination, the qualified people can achieve “receiving everything” and gradually build an immune barrier among various groups of people to stop the spread of the novel coronavirus in China.

The formulation of such an inoculation strategy is mainly based on the domestic epidemic situation and the needs of prevention and control work. At present, the focus of prevention and control is “external defense input, internal defense rebound”.

Therefore, the key population inoculated recently gives priority to people with high risk of infection such as imported cold chain logistics, ports, international and domestic transportation.

If they are immunized, they are equivalent to building a barrier for more people in their daily production, living place or environment.

Zhang Wenhong, director of the Department of Infectious Diseases of Huashan Hospital affiliated to Fudan University, judged that in the future, after vaccination reaches a certain level, COVID-19 will become a seasonal respiratory infectious disease close to the flu.

However, no coronavirus vaccine has been officially approved for sale in China.

It is understood that the two inactivated vaccines produced in Chinese medicine and one inactivated vaccine in Kexing are mainly used for vaccination.

Both Britain and the United States have recently revealed that some people have severe allergic reactions during vaccination, which makes people’s nerves tense again: Is the safety and effectiveness of China’s vaccine guaranteed when it is put into use in a hurry?

In response, Zheng Zhongwei, head of the special vaccine research and development team of the scientific research and research and control mechanism of the Joint Prevention and Control Mechanism of the State Council, introduced that the phase I, phase II and III clinical trials of China’s novel coronavirus vaccine, as well as the nearly one million vaccine emergency vaccinations that China has carried out under the premise of voluntary and informed consent in accordance with the law and regulations, fully show that China’s coronavirus vaccine is very safe, with some mild adverse reactions, but no serious adverse reactions.

At the same time, in the process of emergency use, more than 60,000 vaccinators in China have been to high-risk areas abroad, and so far no serious infection case has been reported, which proves that China’s vaccine has a certain protective effect from another perspective.

However, the final effect of the vaccine remains to be analyzed at the end of phase III clinical trials or the results of the middle term blindness.

Normalized prevention and control must not be slackened.

The virus is extremely cunning. Globally, the spread of the COVID-19 epidemic is accelerating. Recently, the average number of new confirmed cases and more than 10,000 new deaths per day worldwide, the highest since the outbreak of the epidemic.

Since China entered December, Chengdu, Fenhe, Beijing, Dalian, Guangzhou and other places have reported new local distribution cases or aggregation epidemics, indicating that the domestic epidemic prevention and control situation is still complex and severe.

“The application of vaccines, especially giving priority to vaccination for high-risk people, provides new technical means to control the rebound of the epidemic this winter and next spring, and also makes us more confident and calm to respond to the epidemic that may occur this winter and next spring.” Wu Zunyou, chief epidemiologist of the Chinese Center for Disease Control and Prevention, said.

However, he also reminded that this winter and next spring to prevent the rebound of the COVID-19 epidemic, we should not bet all on the vaccine.

The reason is that it takes some time for individuals to produce protective antibodies.

For the group, it is expected to form an immune barrier only if a sufficient proportion of people are vaccinated, which will take some time.

Wu Zunyou said that personal protective measures such as wearing masks, social distancing and washing hands frequently are still the simplest, easiest and most effective personal protection measures to prevent infection.

At this stage, all prevention and control measures should still be adhered to.

In addition, the risk of infection caused by cold chains or imported goods has attracted much attention in recent days. Since the second half of this year, several clustered or sporadic cases have occurred due to cold chain or imported goods.

Moreover, in December, more than 10 provinces have reported positive nucleic acid tests such as cold chain food or outer packaging.

On December 17, 2020, a staff member passed the loading and unloading platform of the centralized supervision warehouse of imported cold chain food in Lianyungang City, Jiangsu Province, and the cold storage site of Jiangsu Tianyuan Logistics Group Co., Ltd. Picture/Visual China

However, ordinary people do not need to worry too much about this.

“For the vast number of consumers, the risk of infection caused by purchasing and eating imported cold chains is very low.” Wu Zunyou mentioned that first, the fragments of live viruses, dead viruses and viruses may be nucleic acid positive, that is to say, nucleic acid positive does not necessarily mean that it is infectious.

Second, when testing in the laboratory, CT value is an objective indicator to determine that nucleic acid is negative. The higher the CT value, the less pollution. The lower the probability of containing live viruses.

The lower this value, the higher the pollution, the higher the probability of containing live viruses. Most of the imported cold chain food and goods detected in the country belong to high CT value, that is to say, pollution is relatively light.

Because pollution causes infection, generally speaking, it must be relatively large in pollution, and it also takes long-term repeated contact to cause infection. Therefore, cold chain-related employees, especially logistics loaders, are relatively infected. For consumers, even if they accidentally buy contaminated food, “as long as they keep their hands clean and keep them separated from raw and cooked, the risk of infection will be very small.”

Vaccine development has taken into account viral mutation.

For people’s recent fears, the impact of the COVID-19 mutation may not be so serious.

Recently, the United Kingdom, South Africa and Nigeria have disclosed mutant COVID-19, and some analysis shows that the estimated infectivity of mutant COVID-19 found in the United Kingdom has increased by 40% to 70%, and the transmission index has increased by 0.4.

“A virus, as a very simple creature, is a normal phenomenon to mutate.” Wang Huaqing said at a recent press conference of the Joint Prevention and Control Mechanism of the State Council that generally speaking, this mutation will not affect the severity and infectivity of the disease, nor will it affect the immune effect of vaccines against the virus.

It is reported that the World Health Organization, relevant institutions in various countries and vaccine research and development enterprises have been paying attention to the mutation of the virus and are also carrying out relevant research.

Current research results show that on the one hand, the mutation of the virus is still within the normal range; on the other hand, the relevant units in China use antibodies produced by the vaccine developed in the early stage to neutralize viruses from different sources, including foreign strains, and the immune effect is relatively good, and no mutation has been found to be effective against the vaccine. Effect of fruit.

Zhang Wenhong said that COVID-19 is an RNA virus that naturally changes as the virus replicates.

Thousands of mutations have emerged, but only a few may be important and change the virus in a perceptible way.

“There is little chance that mutations that make the vaccine ineffective occur before it comes out.” He said that there would be no virus evolution without natural selection. Similarly, without the pressure of vaccines, it is basically impossible to naturally screen out viral variants that are invalid for vaccines.

At present, the vaccine will produce antibodies against many regions of S protein, and a single mutation is unlikely to reduce the effectiveness of the vaccine. Over time, more mutations occur, and once mutations that are found to be ineffective against the vaccine, it is easy to adjust the vaccine.

The heads of many vaccine research and development enterprises were also optimistic about the problem of virus mutation in an interview with Caijing National Weekly.

The person in charge of an enterprise focusing on inactivated vaccines told reporters that the risk of mutation was considered from the beginning. When doing vaccine research, dozens of strains from many regions and different countries in China were included.

The analysis found that although these strains have changed in nucleic acid sequence, the virus itself has not changed. The antibodies produced by the vaccine can still neutralize the virus.

The person in charge of Ayvexin Biopharmaceuticals, which mainly focuses on nucleic acid vaccines, said that the DNA vaccine it developed corresponds to the gene sequence of Spike Glycoprotein, even if the Spike protein or other sequences change slightly, the resulting And antibodies still have a protective effect. For major mutations, nucleic acid vaccines can be easily sequenced and redeveloped.