How to deal with the second wave of the global epidemic
China News Weekly reporter/Huo Siyi
Published in the 969th issue of China News Weekly on October 26, 2020
Since September, the epidemic has rebounded all over the world, with Europe and the United States showing the most obvious performance.
According to statistics from Johns Hopkins University, as of October 20, there have been more than 40 million confirmed new crown patients worldwide and more than 1.11 million deaths.
The number of confirmed cases in the United States has reached 8.21 million, with more than 220,000 deaths.
In the past week, the United States experienced its worst epidemic situation since August, with more than 60,000 new diagnoses every day, and even close to 70,000 at one time.
Within one month, the number of new diagnoses in a single day in the United States doubled.
In Europe, daily new diagnoses in many countries have set new records.
WHO data shows that in the second week of October, the number of cases reported in Europe was nearly three times higher than at the peak of the first epidemic in March.
Inpatients are increasing, and intensive care beds in many cities will reach full capacity in the coming weeks.
The WHO warned that if the menacing wave of the epidemic is not paid enough attention, by the beginning of next year, the mortality rate in the entire EU may be 4 to 5 times higher than in April.
According to the prediction of the model team of the University of Washington in the United States, based on the current spread of the new crown and weather conditions, the death toll in the United States will double by January 2021 and may reach 400,000 by the end of January, which is equivalent to the number of deaths in the United States during World War II. .
The second wave of the epidemic is dominated by young people
At present, the academic community has reached a consensus that entering the autumn, the second wave of epidemics in the world has arrived.
Chen Xi, associate professor of global health policy and economics at Yale University, told China News Weekly that the so-called "second wave" refers to the second peak on the transmission curve.
The number of new diagnoses in France has soared since the end of August, breaking the record close to 80,000 on October 19.
Since October in the United Kingdom, the daily increase has gradually approached 20,000, nearly three times the number in September.
In contrast, the rising trend of death is more worrying.
In the number of new deaths in a single day, 150 cases were reported on October 17, which became the highest record since June 10 this year.
Germany, where the epidemic has been stable, is no exception.
According to data from the Robert Koch Institute, the country’s disease control agency, on October 17, 7,830 newly diagnosed cases in Germany in a single day, reaching the highest record since the outbreak.
At the beginning of October, this number had not exceeded 2,000.
From the number R0, the severity of the spread of the new epidemic in Germany can be more clearly seen.
Previously, the premise for the resumption of work in Germany was that the basic infection number R0 was lower than 1.
German Chancellor Merkel has tirelessly emphasized in every public meeting that when the value of R0 is greater than 1, every small increase will trigger a new exponential growth.
But since the end of September, R0 has been greater than 1, on October 17, R0 has reached 1.37.
In this round of transmission, the seasonal characteristics of the spread of the new coronavirus have been proved.
Lu Mengji, a Chinese-born German virologist and a professor at the Institute of Virology at the University of Essen School of Medicine, told China News Weekly that the new coronavirus is a coronavirus. The seasonal characteristics of this type of respiratory virus are very obvious. It can survive on the surface of objects under low temperature conditions. Longer, it promotes the spread of the virus among people.
In addition, due to the colder temperature and the increase of indoor activity time, more small-scale gatherings have appeared in enclosed spaces.
Chen Xi also pointed out that the seasonal factors of this wave of the epidemic in the United States are very prominent. The situation in the north is more serious than that in the south. Nine states set a single-day record of newly diagnosed cases on October 16, including Wyoming, Minnesota, and Wisconsin. States, West Virginia, North Dakota, Indiana, New Mexico, Utah and Colorado, mainly in the Midwest and North.
Compared with the first wave, the second wave of the epidemic has some distinct characteristics.
Taking Germany as an example, Lu Mengji pointed out that the peak of the epidemic in Germany in March and April this year was mainly imported. Most of the infected people carried the virus back home after skiing in neighboring countries such as Italy and Austria. Large-scale local outbreaks, limited scope of impact, clear transmission trajectories, and timely isolation of infected persons can well control the epidemic situation.
In fact, just a few weeks ago, most cases could still be traced to the source.
But now, the situation is very different.
Germany stipulates that if the number of newly diagnosed cases per 100,000 people exceeds 50 within a week, the area in which it is located must consider strengthening control or re-blocking.
Because 50 happens to be the upper limit of traceable cases in a region, more than 50 cases means that all possible infections in the region cannot be locked, and the spread of the new coronavirus cannot be effectively blocked.
On September 20, there were only 3 areas with more than 50 cases, and by October 17, it had reached 84.
In addition, a lot of this round of transmission in Germany occurred in private gatherings, such as some religious activities or gatherings of young people in bars.
Especially the latter is very common, which also increases the difficulty of tracking.
In his view, the second wave of the epidemic has a prominent feature: the number of young people has increased.
According to data from the Robert Koch Institute, in the past two months, the main group of newly infected people each week is from 15 to 34 years old, followed by 35 to 59 years old and 5 to 14 years old. In March and April, the infection The largest group is the elderly over 80 years old and the 35-59 years old man.
This trend can be seen more clearly from the change in the average age of infected persons in a week.
In the first wave of the epidemic, the average age of the infected was around 45 years old, and since September it has dropped to around 30 years old.
Since many young people are asymptomatic infected, it is difficult to identify them, and it is easy to bring the virus home to the elderly, and the average age of infected people has rebounded.
According to the latest statistics, in the week of October 12, the average age of the infected person was 39.
Lu Mengji said that at this moment, the German epidemic has evolved from an imported small local spot outbreak to a local multi-"hot spot" outbreak, and a large-scale community spread has formed.
Regardless of the transmission scenario, transmission trajectory, transmission speed or source, the second wave of epidemics is very different from the first wave.
Similar characteristics can be observed in other European countries and the United States.
Many epidemiologists pointed out to China News Weekly that in the second wave of epidemics, firstly, the spread of the community was further expanded, showing a multi-point outbreak, which is more difficult to track; secondly, it was mainly spread by small indoor gatherings; Third, young people are the main infected people.
"This is similar to the spreading trajectory of influenza many times in the past. The seeds have been planted in the first wave, and when the temperature is right, they will begin to germinate." Lu Mengji said.
Revisit the fantasy and reality of herd immunity
With the advent of the second wave of the epidemic, many countries have strengthened control measures. At the same time, leaders of some countries have expressed their intention to block a second time, but this has triggered a strong backlash.
On October 5th, Martin Kurdoff, a professor of medicine and biostatistician at Harvard University Medical School, and Sunitra Gupta, an epidemiologist at Oxford University, and Jay Bata, a professor of medicine at Stanford University Charya publicly released the "Great Barrington Declaration" (referred to as the "Declaration"). As of October 19, more than 10,000 people worldwide signed it.
The "Declaration" stated that before the advent of the vaccine, continuing to adopt general blockade measures will cause irreversible losses, and vulnerable groups will also suffer greater harm.
The previous lockdown policy has also had a devastating effect on short- and long-term public health, such as reduced childhood vaccination rates, worsening cardiovascular disease patients, reduced cancer screening, and worsening mental health.
In addition, it is a serious unfairness to let students drop out of school.
The "Declaration" provides a solution, a disguised "herd immunity", that is, a strategy of "protecting key populations".
Prioritize protection for high-risk groups such as the elderly, but let young people with low mortality risk basically resume their normal lives. Schools must be reopened. Young people should go to work normally, restaurants and enterprises should be open normally, and cultural, recreational and sports activities should also be carried out. restore.
Martin Kurdoff, one of the initiators of the "Manifesto" and a professor of medicine at Harvard Medical School, told China News Weekly that young people are both low-risk and socially active.
If they can produce immunity as soon as possible, the threshold for the entire society to achieve herd immunity will be lower.
He explained that the logic of this strategy is that although it is impossible for everyone to get 100% protection, instead of shifting the risk of infection from young low-risk groups to the elderly, it is better to go the other way.
In the eyes of Kudov and others, this is the "most compassionate" approach at this stage.
But many scholars hold the opposite view.
Greg Gonçalves, an assistant professor of epidemiology at Yale University School of Medicine, said fiercely on Twitter that he believed that “herd immunity” without a vaccine would be tantamount to a massacre.
After the "Declaration" was published, it caused huge controversy and opposition.
Just 10 days after its release, "The Lancet" published another manifesto against it, called "John Snow Memorandum" (referred to as "Memorandum").
John Snow is one of the founders of modern epidemiology. This memo has been signed by more than 4,000 people.
Some experts pointed out that although the three sponsors of the "Declaration" are top experts in their fields, they are not specialized in epidemiology.
The "Memorandum" pointed out that any pandemic management strategy that relies on natural immunity is flawed.
The uncontrolled spread of the virus among young people will bring about a high infection rate and a higher mortality rate for the entire society.
These infected young people will affect the labor market, and the impact on the medical system will also make it overwhelmed.
Empirical evidence from many countries shows that it is not feasible to limit uncontrolled outbreaks to specific segments of society.
Many experts analyzed the "China News Weekly" and specifically the "Great Barrington Declaration". This infeasibility is first reflected in this: A prerequisite for this disguised "herd immunity" is that the risk of new crown infections at different age levels has been clarified. That is, the elderly are high-risk, and the young are low-risk.
But the question is, how should the so-called "low risk" of young people be defined?
The basis given in the "Declaration" is that the probability of death after being infected with the new crown is more than a thousand times higher for the elderly and infirm than the young.
For children, the risk of COVID-19 is even lower than many other epidemic diseases, including influenza.
Kudov told China News Weekly that this conclusion came from a study based on Wuhan data.
The use of early Wuhan data is to better reflect the true spread of the new coronavirus before social distancing measures were adopted.
The "Memorandum" stated that there is no evidence that young people have long-lasting protective immunity against the new coronavirus after they are naturally infected. Once the immunity is reduced, the local transmission caused will bring greater risks to high-risk groups, and this strategy It will not end the pandemic of the new crown, but will lead to recurrent epidemics, just like many infectious diseases before the birth of the vaccine.
This will also bring an unbearable burden to the economy and medical staff.
In addition, the frequency of second-degree infections is unclear, although there are only very few cases.
"This is a dangerous fallacy lacking scientific basis." More than 4,000 experts protested.
For the United States, Chen Xi said, the flaw of this strategy is that it does not take into account the high proportion of obese young people.
In theory, achieving herd immunity requires 60% to 70% of the population in an area to gain immunity, but this refers to healthy people.
According to statistics in the United States, among young people aged 20 to 39, the proportion of obesity is about 40%, and among middle-aged people aged 40 to 59, the proportion of obesity is 44.8%.
The existing medical evidence shows that obese people are 74% more likely to enter the ICU after being infected with the new crown, and the probability of death is 48% higher.
"Although it is cruel, the United States simply does not have enough healthy people to resist the risk of new crowns. In this case, how to achieve herd immunity?" Chen Xi said.
In addition, another fatal flaw of this strategy, as Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in the United States, said that “we have enough power to protect the elderly” is that Very ridiculous and unreasonable.
What happened in the past has shown that this is far from the truth.
Allowing the virus to spread uncontrollably among the population will expand the already serious community transmission and cause more deaths among the elderly.
After the "Declaration" was released, Fauci immediately accepted an interview with ABC and made the above remarks.
According to media statistics, as of the end of August, 42% of deaths due to the new crown in the United States occurred in nursing homes and nursing institutions for the elderly.
The "Memorandum" also emphasizes that the experience of countries such as Vietnam and New Zealand has shown that strong public health response measures can control transmission and restore life to a near-normal level.
These evidences have pointed to a very clear path: before a safe and effective vaccine is produced, controlling the spread of the new crown in the community is the best way to protect society and the economy.
"We cannot afford the destructive consequences of lifting restrictions and must take urgent action." The "Memorandum" reads.
In fact, the tit-for-tat confrontation between the "Great Barrington Declaration" and the "John Snow Memorandum" is also a clash of two epidemic prevention ideas. One hopes to be liberalized as much as possible, and the other believes that strengthening control is more necessary.
Before the resumption of work for the first time, countries vacillated between the two roads.
Now facing the arrival of the second wave of the epidemic, the choice becomes more difficult.
Judging from the various controversies triggered by the Great Barrington Declaration, the complexity of this issue has exceeded expectations.
Its essence still lies in how to make a more reasonable trade-off between protecting the social economy and achieving the goal of epidemic prevention?
The signatories of the Memorandum, which supports control, also acknowledge that continued restrictions have led to widespread morale and public trust in the policy.
"Therefore, in the face of the second wave of epidemics, people have developed a new interest in herd immunity." The "Memorandum" wrote.
Details determine the success or failure of epidemic prevention
"Let the virus spread freely, or shut down our society completely," said WHO Director-General Tan Said at the regular press conference of the World Health Organization (WHO) on October 12.
Facing the menacing second wave of the epidemic, Michael Miner, an assistant professor of epidemiology at Harvard University School of Public Health, believes that a "one size fits all" general blockade should definitely not be adopted again.
Even from the perspective of simply curbing the spread of the virus, the blockade policy is "too slow" for controlling the new crown, he told China News Weekly.
Miner and his colleague, Harvard Professor of Economics, and James Stoker, who served on the White House Economic Advisory Committee, jointly studied the impact of different degrees of blockade on the economy and epidemic prevention under the second wave of the epidemic. To this end, three simulation scenarios were constructed.
In the first scenario, no blockade measures are taken.
However, the fatigue and numbness caused by the last wave of blockade made people relax to the pre-pandemic level in the practice of daily protective measures.
It is predicted that the death toll from the new crown in the United States will soar to 450,000 in January.
It is estimated that by the end of this year, the unemployment rate will reach 7.5%.
In the second scenario, the governors of the US states blocked most companies but did not implement daily protective measures. The results showed that only the death toll was reduced by 375,000, but the unemployment rate rose to 15%.
In the third scenario, the company remained open, but under the guidance of the US CDC, strict protective measures were taken, such as maintaining adequate tests, timely isolation, and special measures to protect the elderly. These measures prevented the second wave of the epidemic. The large-scale spread.
The results show that this strategy is optimal, with only 160,000 deaths and an unemployment rate of 6%.
"Our simulation results show that it is neither necessary nor meaningful to block the economy. It will only cause unemployment but will not prevent death." Mina said.
Experts pointed out that in the ideal model constructed by Miner and others, the strategy for the third scenario is the third middle way that countries should take to achieve the greatest economic and epidemic prevention effects at the least cost.
In reality, the strategies adopted by many countries are variants of this model, but from the perspective of objective epidemic prevention results, there are big differences.
The core of success lies in the level of implementation of the details.
For example, is a mask worn?
Do people strictly observe social distance?
Is the large-scale daily rapid inspection realized?
Can every close contact be traced and effective isolation guaranteed?
Are health protection measures in public places strictly enforced?
These sound like clichés.
But Miner pointed out that the surprising fact is that after so many months, Americans are still discussing the necessity of wearing masks, and some states allow large-scale gatherings.
More importantly, the United States is still severely under-tested for the virus.
In fact, after experiencing the peak in June and July, the epidemic situation in the United States began to decline steadily in August, from the previous daily increase of nearly 70,000 to about 30,000.
At that time, if the epidemic could be controlled and the chain of community transmission cut off, this wave of autumn and winter epidemics would not have been so serious.
"But the United States has missed the best prevention and control period," Chen Xi sighed.
In addition, a prominent feature of this wave of epidemics in the United States is the same as that in Germany. Most of the young people are infected, but the cause is different from Germany.
Unlike in Germany, where mass transmission mainly occurs in bars, there are many young people infected on campus in the United States.
Chen Xi pointed out that the condition for the resumption of the university must be adequate testing. For example, his Yale University mandates that all students undergo two tests a week, but most schools only test students who feel unwell and actively apply.
But he also believes that Yale’s experience is difficult to replicate, not only because of its ample funding, but more importantly, the school’s decision-making level attaches great importance to public health. The current Yale principal Peter Saloway is a part-time faculty member at the School of Public Health, so he is very Epidemic prevention and control are very concerned and respect science.
Failure of the "brake mechanism"
Unlike the United States, Germany is among the forefront of developed countries in details such as testing, wearing masks, and tracking. However, facing the second wave of the epidemic, it still encountered challenges when adjusting its epidemic prevention strategies.
On October 14, German Chancellor Merkel summoned the governors of the states to Berlin for a face-to-face meeting.
This move shows the severity of the current epidemic in Germany.
The last face-to-face meeting was on March 12, at which it was necessary to decide whether Germany would open the blockade.
After eight hours of discussion, the federal government and the states made several "very small changes" to Germany's existing epidemic prevention policies, as Lu Mengji described in China News Weekly.
For example, in areas where there are more than 50 new confirmed cases per 100,000 people a week, masks should also be worn in crowded outdoor occasions, and indoor family gatherings cannot exceed 5 people; more than 35 new cases per 100,000 people per week For example, indoor family gatherings cannot exceed 10 people.
Previously, Germany's epidemic prevention strategy was praised for its flexible "brake mechanism".
Each state closely observes the number of newly diagnosed cases per 100,000 people a week. If it exceeds 50, an "emergency brake" will be activated to moderately tighten policies, such as shortening the operating hours of bars and restaurants.
The UK also adopts a graded epidemic response mechanism.
In the early stage of the resumption of work in May this year, British Prime Minister Boris Johnson announced the five-level alert system, but on October 14, Boris adjusted the five-level response to a “three-level lockdown” and said it was to “simplify the standards. And strengthen restrictions in some cases."
The classification standard between different levels is also the number of new infections per 100,000 people per week.
Compared with Germany, the valve design in the UK is higher, with 100 cases.
But in fact, the total population of Germany is nearly 20 million more than that of Britain.
Lu Mengji analyzed that the German valve was designed to be smaller and therefore more sensitive. After Merkel's meeting this time, the threshold was lowered to 35 cases, indicating that the policy is more detailed, and it also shows that the policy room is very small, only in numbers. Further fuss.
In fact, among the 400 districts in Germany, 84 districts have more than 50 cordon lines, but these districts have not taken too many additional blockade measures.
In this German outbreak, small family gatherings were the main source, and law enforcement agencies had no right to enter private households for supervision.
Germany's flexible dynamic adjustment mechanism between blockade and deregulation seems to be a little out of order.
Lu Mengji further pointed out that for countries such as the United Kingdom and Germany that have adopted hierarchical epidemic prevention strategies, their current predicament is not the erratic movement between blockade and deregulation, but the exhaustion of measures that can be taken. As a result, the implementation of the policy is limited.
The limited central power of the federal government and Western people's concern for personal freedom and privacy and other factors have prevented many restrictive measures from being implemented.
In the face of the second wave of the epidemic, the real test is the degree of people's autonomous compliance with policies.
"In Germany, 85% of people are very conscious. They wear masks, reduce private gatherings, and strictly respect protective measures in public places. But even if only 15% of people do not follow the rules, it will cause the spread of the community transmission chain, and this Many of these groups are young people, and these transmissions are difficult to track." He said.
After the first round of blockade and resumption of work, now looking back at the pros and cons of epidemic prevention in various countries, Chen Xi summed up three more essential standards: one is decisive government decision-making, the other is effective communication between the government and the public, and finally Whether the public is willing to comply with the epidemic prevention policy.
These three points can determine the success or failure of each country's epidemic prevention, and the United States has not done well on these three points.
Regarding the trend of the global epidemic in the next few months, Lu Mengji predicted that, based on the characteristics and spread of this wave of epidemics, it is unlikely to weaken by the end of this year.
At present, everyone must raise their awareness of self-protection; the second is to strengthen the protection of high-risk groups.
Regarding the world picture after the vaccine arrives, many experts have said that the future may not be too optimistic, but there is no need to be too pessimistic.
Since vaccines will be vaccinated in batches among different groups of people, the world will still swing between blockade and openness for at least two to three years.
China News Weekly, Issue 39, 2020
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