The British government began to lift a large number of anti-epidemic restrictions on July 19, and now nearly two months have passed. This is the first step taken by the UK to adopt a strategy of "coexistence with the new crown virus" (hereinafter referred to as "coexistence strategy"). While British policymakers are exploring the implementation of this controversial strategy, other European and American countries are also waiting and watching. If the coexistence strategy works well, European and American countries will follow suit one after another, which will have a profound impact on the global response to the new crown pneumonia epidemic.
The United Kingdom experienced infections caused by the delta mutant strain earlier than other Western countries. As the proportion of vaccinations in the United Kingdom exceeds that of many developed countries, including the United States, this makes the United Kingdom an experimental field for implementing coexistence strategies. To what extent can the new coronary pneumonia become the same as other common respiratory diseases? In this process, the British government released a large amount of data so that the outside world can closely follow the progress of the epidemic.
According to data released by the British Ministry of Health on August 21, there were 32,058 newly diagnosed cases of new coronary pneumonia in the UK in the past 24 hours, with an average of 31,000 in the seven days. At the same time, the number of hospitalizations has not increased significantly, and the number of deaths is far below the initial level of the epidemic. The number of daily hospital admissions due to the new crown virus in the UK peaked in January this year, at 4,200 per day. In July, the maximum number of admissions reached about 900 per day. Data on August 14 showed that the average number of admissions in the seven days was 838. The daily death toll in January reached 1,200, and the current seven-day average is 100.
Although there are 30,000 new cases and nearly a hundred deaths every day, this number is still lower than the previous estimates of some infectious disease scientists. After the epidemic is unblocked, the number of new cases in the UK may reach 100,000, 1,000. People are hospitalized, and it may even reach 200,000 cases per day, and 2,000 people are admitted to the hospital.
Eradication of the new coronavirus is no longer possible
British public health experts have different interpretations of the current situation of the epidemic, which also reflects their different thinking in dealing with the epidemic, that is, whether to adhere to a "zero transmission" strategy or to choose a coexistence strategy. In the eyes of some people, the current situation suggests that the latter strategy seems to be working, because vaccines play an important role in controlling the number of cases and ensuring that the number of hospitalizations and deaths is reduced, even though school holidays, weather and other factors are also reducing transmission.
This view is supported by certain data. At present, the average daily number of vaccination in the UK exceeds 220,000 doses, and 62% of the total population and 75% of adults are fully vaccinated. According to statistical analysis of blood samples, the British government estimates that 90% to 94% of British adults have a certain degree of immunity to the new coronavirus because they have received at least one dose of the vaccine or have been infected with the new coronavirus before.
Professor Paul Hunter, an epidemiologist at the University of East Anglia in the United Kingdom, agrees with this view. In his view, the infection situation in the UK is approaching an equilibrium, and vaccination means that the new crown virus is not It is too likely to trigger a new wave of large-scale infections as in the past, but it may still lead to scattered epidemics, especially in areas with a low degree of protection.
This balance cannot be equated with achieving herd immunity. Hunter pointed out to the Caijing reporter that it is impossible to achieve herd immunity against the new coronavirus because we have not achieved herd immunity against any kind of coronavirus.
"A balance is reached like when humans encounter other coronaviruses, that is, mass vaccination can ease the epidemic, but it will still recur, causing human illness or even death." Hunter said.
Hunter is a representative public health expert supporting coexistence strategies in the UK. He does not support the implementation of a "zero transmission" policy in the UK, because the new crown virus has developed into an endemic stage in European countries such as the UK, which means that the disease may spread locally for hundreds of years. In the case of the vaccine, the new coronavirus will also be repeatedly infected. In this state, implementing a zero-infection strategy to interrupt transmission is of little additional value, because public health intervention has never prevented transmission, only delayed it.
Regarding the evolution of the new crown virus, many experts in related fields hold similar views as Hunter, that is, the new crown pneumonia has or will develop into an endemic epidemic. In January this year, the scientific journal Nature asked more than 100 immunologists, virologists and health experts around the world whether the new coronavirus can be eradicated? Nearly 90% of respondents said no. There is evidence that the new crown virus may become an endemic virus and continue to spread around the world.
This is nothing new. The influenza virus and the four coronaviruses that cause the common cold are endemic viruses. The World Health Organization estimates that between 290,000 and 650,000 people die from influenza-related diseases each year. But these diseases have become controllable, and the death toll is to be expected. Scientists hope that the new coronavirus is the same. In this case, the virus will continue to exist, but people will develop a certain degree of immunity to it through vaccination and natural infection, resulting in fewer severe cases, and the number of hospitalizations and deaths will not remain at the current rate. scale.
"The severity of the second infection with the new coronavirus is almost always lower than the first, and the severity of the infection after vaccination is also lower. Therefore, it will not be long before the new coronavirus will become another cause of the common cold." Heng It is especially emphasized that the new crown virus may be the cause of the common cold, and the new crown virus cannot be equated with the influenza virus.
Change epidemic prevention strategy
Based on the scientific judgment that the new crown pneumonia has a high probability of becoming a local epidemic, and the mass vaccination has made the most deadly stage of the epidemic basically over, the governments of European and American countries are considering whether to no longer resort to strict national lockdowns to control it. The epidemic has turned to seek a long-term, low-intensity model to coexist with the virus.
In addition to the United Kingdom, countries such as Germany, Italy, and France have also shifted from seeking to end the epidemic to preparing to coexist with it. Governments are formulating plans to take vaccinations, masks, frequent testing, and limited social distancing measures to contain the new crown virus before the third epidemic winter arrives in the region.
In Asia, the Singapore government has also chosen to change its anti-epidemic strategy, largely because the country’s special role as an international shipping center prevents it from always adopting a zero-spread strategy to deal with the epidemic. The media used Singapore as an experimental comparison with the UK, but Singapore’s Health Minister Wang Yikang said that Singapore’s road map is very different from the “big bang approach” adopted by the UK to reopen. What Singapore wants is to take a middle course, in which it is essential to achieve high vaccination rates and maintain containment and mitigation measures.
People line up at a temporary vaccination center in central London on July 16, 2021. Picture/Fox
It is precisely because the British government has launched a coexistence strategy in a radical way that has caused great controversy. Many medical experts are still worried about this and hold objections. Before the British government implemented the relaxation policy, 15 experts published an open letter in the well-known medical journal "The Lancet", questioning the Johnson government's measures to unblock England in a comprehensive manner, calling it "a dangerous and unethical experiment." Today, more than 4,000 scientists, doctors, nurses and other professionals have signed the open letter to show their support.
John Drury, professor of social psychology at the University of Sussex, and Martin Mckee, professor of the London School of Hygiene and Tropical Medicine and European public health expert, are two of the 15 co-authors of this open letter. Bit. In an interview, a reporter from Caijing asked them how they viewed the feasibility of the coexistence strategy. They almost unanimously expressed the view that this is an empty political slogan with no connotation.
"When I hear the word'coexist with the virus', I want to know what people mean." Drewry said. McGee also bluntly said, "So far, no one has explained what it means to coexist with the new crown virus. This is a very convenient slogan, but those who maintain this claim cannot say exactly what it is. Until then, I cannot assess. It."
Speaking of the original intention of publishing this open letter, McGee said that a misunderstanding of the open letter needs to be clarified, that is, this open letter is not a call for the eradication of the virus, because throughout human history only smallpox, a virus, has been completely eradicated. This letter called for the elimination of infection, just as it did with viruses such as measles. Keep the severity of the domestic epidemic at a low level, so that most of the epidemics are related to imported cases, rather than large-scale domestic infections. New Zealand has proven that this is possible. But the main obstacle in the UK is politics, and the Johnson administration has never really made it clear what it wants to achieve.
Suspicion of the British government's aggressive and non-systematic coexistence strategy made McGee and Drewry both feel not optimistic about the current situation of the British epidemic. They did not believe that the strategy worked and the worst expected scenario did not occur. On the contrary, it was an anti-epidemic behavior. The inertia caused the worst scenario to be postponed, but this autumn and winter epidemic is full of uncertainty.
Drewry is a member of the Epidemiological Behavior Research Group (SPI-B) under the British Government's Emergency Scientific Advisory Group (SAGE). He analyzed that the number of cases may not reach the expected level because many people continue to wear masks and maintain social distancing, although they are not required to do so, plus many people still work from home.
At present, most Britons follow the government's advice and remain cautious after the restrictions have been relaxed. According to data from YouGov PLC, a British market research and data analysis agency, about 70% of Britons still wear masks in public places, and this proportion has not changed since the spring of 2020. Not only that, at the beginning of August, the passenger flow of entertainment venues such as restaurants, shopping malls and cinemas in the UK was 7% lower than before the epidemic, public transport usage was 33% lower, and the flow of people going to the workplace was also reduced by 40%.
Most British people still maintain the inertial behavior of epidemic prevention, and Drewry is not optimistic, especially considering that the British government has not issued specific guidelines to guide the public to maintain epidemic prevention behavior. In his view, many British public have the motivation and do everything they can to protect themselves and those around them, but still do not have enough support to make wise decisions or take correct protective actions. If the mask-wearing regulations, the two-meter social distancing rule, and restrictions on large-scale events disappear, the public will not know what they need to do to keep themselves, their loved ones, and the community safe.
"The key point is that if you want to change the regulations so that everyone is responsible for their own risk assessment by conscious and self-discipline, instead of relying on legal constraints, then you need the ability and support that psychologists say. In fact, it is commissioned by the British government. The report made by the SPI-B team called for an epidemic prevention education program to enable people to assess risks and make correct epidemic prevention behaviors. On the contrary, if people do not get the correct information, how can they make wise judgments? People can only be left alone , The consequences would be unimaginable." Drewry said.
The virus continues to mutate, hidden crisis
McGee also believes that it is too early to judge the effectiveness of the coexistence strategy. Monitoring data shows that people's epidemic prevention behavior has not changed much for the time being, and they are still very cautious. It is summer, so people spend a lot of time outdoors and school has not yet started. The epidemic prevention picture is still very complicated. There was a wave of peaks during the European Cup. After the European Cup, the number of cases did decline, but now they are slowly rising. "I am deeply worried about the changes that the epidemic will change in autumn and winter."
The gradual increase in infection cases has made many public health experts see the hidden crisis, that is, the combination of high prevalence and high-level vaccination creates the most likely conditions for immune escape mutations, which SAGE pointed out as early as July.
The so-called mutation refers to the error that occurs when the virus invades the body's cells and replicates at will. The more virus infections, the greater the chance of getting stronger mutations by chance. How strong the virus is depends on how strong people's immunity is. At the beginning of the epidemic, there were many viruses everywhere and there were many opportunities for mutation, but there was no need to be immune to escape, because not many people had immunity. But when most people gain a certain degree of immunity from infection or vaccine, mutation will be of great benefit to the virus.
Based on this principle, scientists pointed out that as vaccines become popular, the spread advantages of viruses that can evade vaccines and achieve immune escape will increase. As Jonathan Ball, a professor of virology at the University of Nottingham, said, when only part of the population has immunity, especially when the virus is still circulating, only some people have immunity, it is destined to stimulate the virus to escape towards immunity. Direction development, this is an unavoidable trend.
SAGE published an analysis report at the end of July to point out the worst scenario for this situation. This report has not been peer-reviewed, but it is believed that a new coronavirus mutation that may make the existing vaccine fail is likely to appear, because the new coronavirus is unlikely to be eradicated, the mutation will continue to appear, and eventually there will be a gradual or intermittent accumulation of antigenic mutations , Which eventually led to the failure of the current vaccine.
This worst scenario does not mean that a new mutation is destined to appear in the UK, but that under the pressure of virus evolution, the chance of mutation appears greater than before. In view of this, the report recommends that the British government should continue to reduce the spread of the virus as much as possible, reduce the infection and spread of vaccinated individuals, reduce the possibility of mutation selection among vaccinated individuals, and ultimately reduce the chance of new anti-vaccine variant viruses. On the other hand, we must vigorously develop new vaccines to cope with mutations, prevent hospitalization and disease, and induce high-level and long-lasting mucosal immunity.
There have been at least four major variants of the new crown virus, including the highly contagious delta mutant strain. It was originally discovered in India and is currently the main cause of the surge in cases in Europe, Asia and the United States. Although these mutant strains have not completely escaped the immune system, they have shown reduced sensitivity to vaccine-acquired immunity.
McGee believes that the Delta strain has shown the challenges brought about by highly transmissible mutations. SAGE's research speculates that there is a certain possibility, which provides a strong argument for reducing cases to the lowest possible level, rather than Let it spread. In his view, there are still many people living in countries like China that implement a "zero transmission" epidemic prevention strategy, but if China pursues a policy similar to that of the United Kingdom, this will not be the case.
However, some scientists remain optimistic about this. In their opinion, although virus mutations that are better at evading vaccines have appeared, they will not completely offset the protective effects of vaccines at once, but will gradually weaken the protection of vaccines. This can be seen in the Delta strain. Almost all infections in the UK are caused by the Delta strain. This mutation is better at causing re-infections and evading the protection of vaccines, especially among those who only receive one dose of the vaccine.
"The emergence of escape mutations may lead to increased transmission for a period of time, but as we have seen in other coronaviruses, each escape mutation is not enough to destroy all protections, nor is it enough to reduce protection against serious diseases. Because the virus will continue to spread, we will continue to strengthen our immunity to serious diseases to deal with escape mutations." Hunter said.
Bauer also believes that it is unlikely that there will be a variant that can evade the vaccine well, can spread quickly, and can make people who have received two doses of the vaccine become severely ill. Because viruses are not invulnerable in all aspects, the choice of viruses in the evolutionary process means that they may have to sacrifice certain characteristics in order to better evade the immune system.
Although there is no final conclusion on the evolution of the virus, in order to avoid the worst, the British government has prepared to provide booster shots of the new crown vaccine from September, in case it needs to increase the protective effect when the immunity caused by the initial vaccination weakens, and Improve protection against new coronavirus variants, and any new mutations in the next few months will be closely monitored.
