Editor's note: How come the metropolises around the world with concentrated medical resources are so vulnerable to the COVID-19 pandemic? Why China has managed to control the outbreak so quickly? Why Western countries and Japan are seeing a resurgence in the coronavirus outbreak? Professor Zhou Muzhi, president of Cloud River Urban Research Institute, offers his interpretation by comparing the COVID-19 responses adopted by different countries around the world.

On Jan. 23, 2020, Wuhan and its surrounding cities like Ezhou and Huanggang announced the suspension of all public transportation such as bus, subway and ferry, temporary cancellation of all flights and trains departing from Wuhan, and temporary closure of all highway entrances to slow the spread of the new virus. The announcement shocked the world. On Jan. 24, Hubei province launched the level I public health emergency response, with other parts of China following suit until all provinces, autonomous regions and municipalities were in the highest level for a public health emergency by Jan. 29. At the press conference of the Joint Prevention and Control Mechanism of the State Council held on Feb. 8, the new infectious disease was named as the Novel Coronavirus Pneumonia (NCP). Later the World Health Organization (WHO) renamed the disease as COVID-19 on Feb. 11.

As the first big city to confront the COVID-19 outbreak, Wuhan saw a surge in coronavirus infections that crippled its medical system. As the virus continued to spread around the world, many cities saw a heavy blow to their medical services. On March 11, the WHO declared COVID-19 a pandemic.

In a study of the medical system overwhelmed by the pandemic, I on April 20 published an article titled "COVID-19: Why is medical system in metropolises so vulnerable?" (Hereafter referred to as the April article) [1]. The article explains why metropolises are so vulnerable to the COVID-19 pandemic and how effective Wuhan was in response to the new disease. It was published on China.com.cn and reposted by over 100 media outlets like people.com.cn, xinhuanet.com and gmw.cn.

On April 21, the English version of the article was published on China.org.cn [2] and later reposted by English media outlets both at home and abroad including the websites of the State Council Information Office of China and China Daily.

On May 12, the Japanese version was published on japanese.china.org.cn[3].

The article analyzes the good practices and lessons learned from Wuhan's COVID-19 response as well as major concerns and measures that should be taken by the medical system amid the pandemic. It serves as a reference for cities around the world in their battle against the novel coronavirus.

After six months, I write this article to explore different measures and effectiveness of the global COVID-19 responses based on the April article with some statistical updates, new diagrams and endnotes.

1. 2019 ranking on health care radiation of Chinese cities

As part of the China Integrated City Index, Cloud River Urban Research Institute has released the 2019 ranking on health care radiation based on a research of 297 cities at prefecture level and above across China. The top 10 are Beijing, Shanghai, Guangzhou, Chengdu, Hangzhou, Wuhan, Jinan, Zhengzhou, Nanjing and Taiyuan. The following 10 are Tianjin, Shenyang, Changsha, Xi'an, Kunming, Qingdao, Nanning, Changchun, Chongqing, and Shijiazhuang. And the next 10 are Urumqi, Shenzhen, Dalian, Fuzhou, Lanzhou, Nanchang, Guiyang, Suzhou, Ningbo and Wenzhou. Please note that Wuhan, the first city to confront COVID-19, ranked sixth.

Jointly developed by Cloud River Urban Research Institute and the Development Planning Department of the National Development and Reform Commission, China Integrated City Index is a system that evaluates growth performance of cities across the country. The institute has been publishing the city index annually since 2016.

The index measures urban development in three dimensions: the environment, society and economy. Under each dimension lies many indicators that support its three sub-dimensions at different layers. The health care radiation is among those indicators.

All of its indicators are supported by 785 data sets, which come from statistical data, satellite remote sensing data, and internet data. China Integrated City Index is a multi-modal index[4] to analyze and measure a city's development through statistical resources of different fields.

The radiation index measures a city's capacity in providing goods and services in certain areas. A high radiation score means the city has the capacity to sell its goods and services, while a low radiation score means that it needs to purchase certain goods and services from other places.

Evaluating a city's health care radiation mainly focuses on the number of physicians and the 3A-grade hospitals. The top 30 cities account for 15% of the certified physicians, 30% of hospital beds and 45% of 3A-grade hospitals in the country. China's medical resources, especially the best hospitals, are mainly concentrated in cities higher in the ranking, which serve local residents as well as people from all around China.

The questions raised in the April article are: Why cities like Wuhan, equipped with one of the top medical resources in China, could be so vulnerable to the COVID-19 outbreak and even overwhelmed by the influx of patients? What should cities do to prepare for future epidemics?


Chart 1: List of top 30 Chinese cities by health care radiation in 2019 Source: Cloud River Urban Research Institute

2. A test for the health care system

Wuhan was the first to confront the COVID-19 outbreak. The city climbed one place to the sixth in the 2019 health care radiation ranking, as it boasts 27 3A-grade hospitals, nearly 40,000 physicians, 54,000 nurses and 95,000 beds. It is hard to expect that a city with such strong health care capacity could be overwhelmed by the coronavirus epidemic.

Other metropolises like New York and Milan are equally vulnerable to the pandemic. Tokyo, which declared?a?state?of?emergency on April 7, was also facing a breakdown of its medical system. The novel coronavirus is indeed a test for the health care system in all global cities.

In the April article, I believe that three reasons are attributed to the breakdown of the cities' medical system.

(1) Overloaded hospitals

One feature of the COVID-19 epidemic is the exponential growth of infections. Especially during the early stage of the outbreak, the surge in infections and social panic have driven a lot of people, whether they were infected or not, to seek testing and treatment in hospitals. This has caused disorder, leaving those who are critically ill unable to receive efficient and quality care. It is also a reason for its high fatality rate. Moreover, the overcrowded emergency rooms, with confirmed cases, suspected patients as well as their families, can also lead to many hospital-acquired infections (HAIs).


Table 1: A comparison of medical resources in China, European countries, the U.S. and Japan in 2019 Sources: China City Statistical Yearbook by the National Bureau of Statistics, OECD.Stat, Kaiser Family Foundation, Ministry of Health, Labor and Welfare in Japan

As is seen from Table 1, the density of physicians in the U.S., Japan and China are only 2.6, 2.5 and 2 per 1,000 people respectively, much lower than that in Germany (4.3), Italy (4) and Spain (4).

Wuhan, with a large concentration of medical resources, has 4.9 physicians per 1,000 people, which is much higher than the national average. But the city's medical system was still overstretched by the outbreak. By May 11, the day before the April article's Japanese version was published, 83.3% of the COVID-19 deaths in China had happened in Wuhan[5], which is believed to be caused by the overloaded hospitals.

Just like in Wuhan, medical workers in the U.S. are also concentrated in big cities. The New York state has 4.6 physicians per 1,000 people, but it is still not enough to avoid a massive breakdown in its medical system.

Italy, one of the hardest-hit countries in the pandemic, has a relatively high density of physicians, counting 4 per 1,000 people, but the country still suffers seriously overloaded hospitals and a breakdown in its health care system. In the Lombardy region where Milan is located, the number of infections has quickly risen from 1,000 on March 2, to over 10,000 on March 14, and to over 40,000 by the end of March. Many patients with critical conditions could not be treated in time due to overcrowded emergency rooms. By May 11, a total of 220,000 people in Italy had tested positive for COVID-19, and the death toll was 31,000, driving the fatality rate to 14%.

Japan's Tokyo has 3.3 physicians per 1,000 people, lower than the level in Wuhan and the New York State. Therefore, the Japanese government has been trying to avoid overcrowded emergency rooms as a key part of its COVID-19 response. The government has established a pre-testing approval procedure to limit the number of testing and advised residents not to go to hospital during the pandemic to reduce hospitalization [6]. Japan's measures are so far effective to reduce the number of HAIs and lower the fatality rate as the medical resources are mostly given to those with critical conditions. By May 11, Tokyo's fatality rate was 5.3%, compared to 7.9% in New York State.


Table 2: A comparison of numbers of COVID-19 confirmed cases, deaths, and death rates in China, European countries, the U.S. and Japan Note: China’s number of COVID-19 infections in this table does not include those are asymptomatic. Sources: Worldometer, Kaiser Family Foundation, stopcovid19.metro.tokyo.lg.jp, website of the Health Commission of Hubei Province

Table 2 compares statistics between May 11 and Oct. 11, showing the COVID-19 infections, death toll, fatality rate and the number of deaths per 100,000 people in China, Japan, the U.S. and major European countries, as well as cities like Wuhan, Tokyo and New York.

By May 11, Spain had 56.9 deaths per 100,000 infections, Italy had 50.5, France 40.4, the U.S. 24.4, and Japan only 0.5. In this sense, Japan successfully controlled the number of deaths in the first outbreak after it avoided a breakdown in its medical system.

From the statistics by May 11, France's COVID-19 fatality rate was up to 19.1%, and the U.K., Italy, and Spain also recorded double-digit fatality rate, while the rate in China and Japan were only 5.6% and 4%. At the same time, the global average COVID-19 fatality rate was up to 12.4%, which dealt a heavy blow to the human society.

However, from May 11 to Oct. 11, those countries and cities had seen a significant drop in COVID-19 fatality rate. During that period, China had zero COVID-19 death cases, while Japan controlled the rate at 1.4%. France and Spain which previously had very high fatality rate managed to lower it under 1%. Even the U.S. which had over 200,000 COVID-19 deaths also lowered the rate under 2.1%.

The reduction was attributable to less crowded emergency rooms compared to the early stage of the COVID-19 outbreak. Though there is no specific medicine that can cure the disease, each country has, to some extent, found ways to treat their patients, which is also key to lowering the rate. Moreover, mass testing is another important reason.

In a period of five months, the global fatality rate lowered to 2.2%. It seems that the new virus is becoming less intimidating. Actually, the rate varies widely between different age groups. Chances of a relatively younger person dying from coronavirus is much lower than that of a relatively older person. For example, Japan's fatality rate in August was 0.9%. By different age groups, the rate for people who are 69 or younger is only 0.2%, but the figure ghastly spiked to 8.1% for those who are 70 or older.

In his address to the Economic Club of New York on Oct. 14, the U.S. President Donald Trump said that 99.98% of the infected under the age of 50 can survive, but the seniors who had underlying conditions have higher risks. Therefore, protecting the high-risk groups through improving the prevention and control system is key to lowering the fatality rate.

(2) A drop in the number of health care workers

A drop in the number of medical staff caused by infections is another feature in this pandemic.

In the early stage of the outbreak, countries lacked knowledge of the coronavirus transmission, and medical staff faced a huge risk of infection due to the shortage of protective resources such as masks, protective clothing, and negative pressure wards. Those factors made testing, sampling, intubation, and other medical practices that are inherently at risk of exposure even more dangerous. As a result, countries have seen a significant decrease in the number of medical staff caused by infections, which also overstretched the medical system.

Infections not only happen in the treatment process. In this March, the extensive isolation and infection resulted from a dinner party attended by trainee doctors from Keio University Hospital also dealt a major blow to the already scarce medical workforce in Tokyo[7].

According to the International Council of Nurses (ICN), data reported by 30 countries showed that at least 90,000 health care workers had been tested positive for COVID-19 as of May 6. By May 5, Spain had 43,956 health care workers infected (accounting for 18% of the country's total infections) and Italy had 19,942 medical staff tested positive for coronavirus, among which 150 physicians and 35 nurses died of the disease.

By Sept. 16, ICN said nearly 3 million health care workers might have infected with the novel coronavirus[8].

From January to June, 48 hospitals in Tokyo have reported HAIs which caused 889 infections among physicians, nurses and patients, and 140 of them had died of the disease. Those infections accounted for 14% of the total number of people who had coronavirus in Tokyo at that time, and the number of deaths resulted from such infections accounted for 43% of the total COVID-19 death toll in the same period. HAIs could not only weaken the medical system, but also lead to new infections among those who have underlying conditions, resulting in a higher infection fatality rate.

Even until October, HAIs were still frequently reported in Tokyo. For example, a hospital in Adachi confirmed on Oct. 15 that 39 patients and 12 staff have infected with coronavirus. A hospital in Nerima also reported 58 new infections, in which 23 were patients.

The super-transmissible coronavirus has severely threatened the safety of medical staff and weakened medical capabilities, resulting in the collapse of the medical system. Therefore, it is critical to avoid HAIs during the fight against COVID-19.

(3) A serious shortage of hospital beds

Since the COVID-19 outbreak, countries have experienced a shortage of medical supplies such as face masks, protective clothing, disinfectant, test kits, ventilators, extracorporeal membrane oxygenation (ECMO) machines, and especially, hospital beds. COVID-19 patients are required to be treated under quarantine to curb the spread of the super-transmissible coronavirus, and severe cases should be treated in intensive care units (ICUs), but hospitals have been in serious shortage of beds in general.

There are up to 13.1 hospital beds per 1,000 people in Japan, the highest in the world. For Tokyo, a city with a total of 128,000 hospital beds, the figure is 9.3. Even so, it already saw a severe shortage of hospital beds during the first COVID-19 outbreak.

In contrast to Tokyo, for every 1,000 people, Italy has a high number of doctors but only 3.1 beds, the U.S. has only 2.9 beds, and New York has only 2.6, which is even lower than the national average. Obviously, inadequate hospital beds have become a bottleneck that restricts medical institutions from receiving patients and hinders timely treatment.

The figure in China is 4.3, a quarter of that of Japan but higher than that of the U.S. and Italy. Wuhan, in particular, has 95,000 beds, or 8.6 beds per 1,000 people, almost as high as that of Tokyo, but it still suffered from a serious shortage of hospital beds in the early stage of the outbreak.

Another problem is that not all hospital beds are qualified for receiving COVID-19 patients for isolation, and the scramble for medical resources has made the bed shortage even more prominent.

3. What are effective responses?

Wuhan, the first city to suffer a collapse of medical system, finally quelled the plague of COVID-19 after 77 days of the lockdown. By mid-June 2020, all parts of China had gradually resumed normal production and life.

How did China quickly cope with the situation? It is extremely valuable for the world reeling from the ravages of COVID-19 to check out China's experience.

(1) Lockdown policy

On Jan. 23, 2020, Wuhan in Hubei province suspended public transportation, closed airports, train stations and other routes leaving it, and asked people not to go outside the city, beginning the so-called lockdown[9]. On Jan. 24, the next day, the whole province activated the first-level response mechanism for major public health emergencies according to the Response Plan for Public Health Emergencies in Hubei province[10]. The response level specifies the degree of various measures to be taken in the identified infected area, and the first-level response requires to suspend work, classes and traffic to avoid any possible personnel flow and close contact[11].

As the upper-level regulation of the Response Plan for Public Health Emergencies of various provinces, municipalities and autonomous regions, the National Response Plan for Public Health Emergencies was formulated based on the experience of combating SARS, and was announced on June 26, 2006, as one of the nation's responses to public health emergencies[12].

Subsequently, other provinces, municipalities and autonomous regions also activated the first-level response mechanism. As of Jan. 29, after the Tibet Autonomous Region activated it, all regions in the entire country had implemented the first-level response mechanism.


Chart 2: Numbers of daily new COVID-19 confirmed cases and deaths during Wuhan's lockdown Note 1: There is no data for Jan. 23, the day when the city began the lockdown, as well as data for Feb. 11. The number of confirmed cases surged on Feb. 12, presumably because it was added up by the figures of the previous day. Source: The official website of the Health Commission of Hubei province.

Chart 2 shows the numbers of new confirmed COVID-19 cases and deaths in Wuhan every day from Jan. 20, days before the lockdown, to Apr. 8, the day when the lockdown was lifted. On Feb. 13, 21 days after the lockdown, Wuhan finally began to see a decline in its daily number of new cases after overcoming various difficulties caused by an unknown virus outbreak, such as the collapse of medical system. On Mar. 18, 56 days after the lockdown, the figure was brought down to zero for the first time. Although a case was confirmed on Mar. 23, the figure remained to be zero for 16 consecutive days until the lockdown was lifted on Apr. 8.

It was undoubtedly a powerful move to lock down the city by cutting off traffic, suspending work, production and classes, and putting in place other measures strictly restricting personnel flow and close contact. Wuhan finally managed to fight back the novel coronavirus after 77 days of lockdown.

China saw the effects of its strict restriction measures throughout the country soon, and its new confirmed cases were quickly brought under control. On Feb. 21, Gansu province took the lead in lowering the response level from the first level to the third and resuming everyday production and life conditionally. Other regions also lowered their response levels from the first to the third since then. On June 13, as Hubei province lowered the level from the first to the third, the response levels across the country were brought down to the third. China has successfully addressed the first wave of COVID-19 thanks to the strict lockdown rules that brought the number of infected cases down to zero.

After that, various parts of China flexibly adjusted their response levels based on local epidemic situations. For example, Beijing raised its response level from the third to the second on June 16 due to a cluster of cases, and strengthened its epidemic prevention and control. As the epidemic was brought under control, Beijing lowered its response level back to the third on July 20.

(2) Quick dispatch of medics

In response to the serious shortage of medical personnel in Wuhan and their drop in number, the Chinese government quickly mobilized a large number of medical staff from all over the country to assist Wuhan. On Jan. 24, 2020, the second day after the lockdown, the Shanghai medical team to assist Wuhan arrived in the city first. It was made up of 136 doctors and nurses from the respiratory departments, infectious disease departments, hospital infection management departments and intensive care medicine departments of 52 hospitals in Shanghai. Eventually, 346 medical teams involving 42,600 medical workers were dispatched to Wuhan and other parts of Hubei province.

The Joint Prevention and Control Mechanism of the State Council introduced at a press conference on Mar. 8 that it usually takes no more than two hours from the time a medical institution receives an order to the time a medical team is set up, and takes no more than 24 hours from the assembly of medical team members to their arrival in Wuhan. The emergency assistance quickly alleviated the pressure on Wuhan in medical terms and effectively saved the city's medical system from collapsing.

It is certain that whether a country can offer its affected area rapid and effective assistance or not is one of the keys to winning over the epidemic, but not all countries are equipped with such capabilities. Judging from the situation in New York and Tokyo, even developed countries with relatively abundant medical resources would find it difficult to mobilize a sufficient number of medical staff to offer assistance in time.

What is even more worrying are those developing countries with a severe shortage of medical resources. Leaving Africa aside, even the neighboring Asian developing countries with large populations, like India and Indonesia, have only 0.8 doctors and 0.3 doctors, and 0.5 beds and one bed in medical facilities, per thousand people, respectively. In such countries with scarce medical resources and insufficient capabilities to offer national assistance, the scramble for medical resources caused by epidemic outbreaks may be extremely severe. Therefore, it is extremely urgent to organize global assistance. The problem is that most developed countries are also suffering from the COVID-19 pandemic and can spare no time to take care of others. At this moment, China's medical assistance to other countries is particularly valuable.

(3) Rapid construction of makeshift hospitals

Wuhan rush-built the Huoshenshan Hospital and the Leishenshan Hospital for severe cases under national support. The two hospitals with high isolation levels are equipped with specialized treatment equipment, and 1,000 beds and 1,600 beds, respectively. The Huoshenshan Hospital opened on Feb. 3, 12 days after the lockdown, and the Leishenshan Hospital was put into use on Feb. 8.

The city also converted stadiums into 16 makeshift hospitals for treating mild cases, and quickly provided 13,000 beds with antibacterial and epidemic prevention levels up to those of first-class hospitals in China. The move channeled mild cases, helping to concentrate high-end medical resources on severe cases, and alleviated the scramble for medical resources.

The experience of Wuhan—building Huoshenshan, Leishenshan and temporary treatment centers to address bed shortage—is worthy of reference and learning for the world.

During the first wave of the COVID-19 pandemic, Japan required some confirmed patients to stay at home for quarantine due to insufficient beds, which was actually an extremely dangerous practice. First, it put the family members of the patients at risk and might lead to infections in clusters within the families. Second, patients could not get effective and professional treatment, and without timely update on health conditions, they might not be able to receive swift referral for treatment when the conditions deteriorated. Fortunately, the practice was largely halted later, and Japan now has also transformed facilities like hotels into isolation wards for patients with mild symptoms, in an effort to channel mild cases and relieve the pressure on hospitals.

A more serious problem in Tokyo is the shortage of ICUs. By 2018, Japan had merely 4.3 ICU beds per 100,000 people, and there was a huge gap compared with the 35 in the U.S., 30 in Germany, 11.6 in France, 12.5 in Italy, and 9.7 in Spain.

Tokyo, which had the largest number of infected cases in Japan, had only 764 ICU beds, or only 5.5 per 100,000 people, when the first outbreak took place. Through various efforts, Tokyo addressed the serious shortage of ICU beds and survived the first wave. However, as the second wave arrives in autumn and winter, there will be a shortage again. A proper solution to it is a key to avoiding a potential collapse of its medical system amid an outbreak.

The countries have adopted a variety of measures to address bed shortage during the outbreaks, with the U.S. even sending naval hospital ships to assist[13]and South Korea taking the emergency importation of a "hospital" as a new option. Faced with a desperate shortage of beds amid the outbreak, South Korea imported an entire "Huoshenshan Hospital in slabs" from the Broad Group in China. The prefabricated stainless-steel slabs made up negative pressure isolation wards in South Korea. Equipped with fresh air systems and ozone technologies, the wards have the highest level of protection against cross infection. The project took only two days locally before the wards were put into use.

4. Is there a trade-off between protecting economy and protecting people's lives?

In the responding policies taken by countries around the world to contain the pandemic, the focal point is how to strike a balance between public health and the economic impact. Through rigorous lockdown measures, China successfully contained COVID-19. China is currently trying hard to maintain the "zero COVID-19 case" situation. China's COVID-19 response can be called the "Zero COVID-19 Case Policy".

On the contrary, most Western countries reopened economy when there were still infections, although they had placed various restrictions on people's activities, such as imposing lockdowns or declaring a state of emergency. The measures taken by those countries can be called the "Coexisting with COVID-19 Policy".

The second part of the article will compare the "Zero COVID-19 Case Policy" and the "Coexisting with COVID-19 Policy" and verify an efficient route to fight against the disease.

(1) China: Prioritizing COVID-19 response

In the aftermath of 2002-2003 SARS, the Chinese government formulated the Regulation on the Urgent Handling of Public Health Emergencies, the National Response Plan for Public Emergencies, and the National Response Plan for Public Health Emergencies, on the basis of the Law of the People's Republic of China on Prevention and Treatment of Infectious Diseases. In 2007, the Emergency Response Law of the People's Republic of China was announced, further systemizing the above-mentioned law, regulation and response plans. On Jan. 20, before Wuhan was put into a lockdown, China's National Health Commission released a statement to classify the novel coronavirus pneumonia as a category B infectious disease under the law on prevention and control of infectious diseases but take preventive and control measures of category A infectious diseases, meaning that the fight against COVID-19 had been launched.

It is exactly because the law, regulation and response plans mentioned above were put into place after the SARS epidemic that China could swiftly impose lockdowns, activate the top-level public health emergency response and take other mandatory measures to curb the novel coronavirus. With a priority placed on epidemic response, mitigation measures would not be altered willfully, regardless of the economic impact. In fact, despite cries for the resumption of production and schools as soon as possible across China, the Chinese government stuck to the requirements for reopening, such as only when there were no new cases.

According to Chart 3, China has done whatever it took in economic terms to prevent the spread of COVID-19, and then resumed normal economic activities soon. Seen in the longer span of time, lockdowns and level II public health emergency response were like strong medicine, but a good therapy to keep the situation under control. It is difficult to keep new case numbers at zero. Therefore, once a new infection case was spotted, China would implement strict restrictions and large-scale COVID-19 testing in the area to prevent the spread of the virus.


Chart 3 Numbers of daily new COVID-19 confirmed cases and deaths in China Note: The number of infection cases in China marked in the chart does not include numbers of asymptomatic cases and imported cases. Source: China's National Health Commission

(2)Report 9and Western countries' responses

On March 16, 53 days after Wuhan's lockdown, British epidemiologist Neil Ferguson and other scientists published "Report 9: Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand". The report predicted that the novel coronavirus would infect eight out of 10 people, with 510,000 deaths in the U.K. over the next four months, if measures were not in place. Even with mitigation measures, such as isolating infected people, home quarantining, and restricting senior people to their homes, there would be still 250,000 deaths in the country. With strict lockdown rules, the death toll could be limited to 20,000[14]. Ferguson told the Science and Technology Committee that the move to balance economy and COVID-19 response while tolerating the spread of the virus to some extent was wrong, noting that lockdown was the only option. On March 23, one week after the report was published, the British government announced a nationwide lockdown, prohibiting residents from going out if not necessary and closing schools and most businesses.

The report projected at most 2.2 million deaths in the U.S. In the light of the report, U.S. President Trump extended the federal social distancing guidelines, which originally expired on March 30, to April 30[ 15].

British journal Nature published a report titled "The effect of large-scale anti-contagion policies on the COVID-19 pandemic" on June 8. The report analyzed the effect of policies rolled out by six countries—China, South Korea, Italy, Iran, France and the U.S. The report estimated that in more than three months from January to April 6, those six countries protected hundreds of millions of people from getting infected, through (1) travel restrictions, (2) social distancing through the cancellations of events and suspensions of educational, commercial and religious activities, (3) quarantines and lockdowns, and (4) additional policies such as emergency declarations[16].

Despite obvious effect, lockdown measures have met a lot of resistance among many people who thought they limited human activities and wrought damage on social and economic activities. Many countries began to lift lockdowns prematurely, after the spread of COVID-19 slowed.

(3) "Zero COVID-19 Case Policy" vs. "Coexisting with COVID-19 Policy"

Wuhan's lockdown was lifted after it met very rigorous requirements. It was only after Wuhan had reported no new cases for the past 16 days that the lockdown was lifted. I think that is the radical "Zero COVID-19 Case Policy".

The Chinese government issued risk-grading criteria on Feb. 17, classifying counties, cities and districts that report no cases or no new cases in the past 14 days as low-risk areas[17].

After successfully containing the first outbreak, China still went all out to maintain the "zero case" situation across the country. Once a new case was confirmed, strict restrictions and large-scale testing would be implemented immediately to block the spread of COVID-19. For example, after three asymptomatic cases were confirmed in Qingdao of Shandong province on Oct. 11, the city tested its entire population and traced people moving out of the city. By Oct. 16, more than 11 million people had been tested.

Contrary to China, European countries and the U.S. lifted lockdown restrictions very soon, because they were eager to reduce the impact of COVID-19 on their economy. A study by the Germany-based IFO Institute for Economic Research and the Helmholtz Centre for Infection Research was released on May 13[18].The study said keeping the Rt (the effective reproduction number, refering to the average number of people who become infected by an infectious person) at 0.75 provides the safest balance between hammering out output and risking a new outburst of infections. In other words, keeping the Rt at 0.75 can minimize the economic costs without jeopardizing the medical objectives. The study is an endorsement of the "Coexisting with COVID-19 Policy" in the academic circle. However, the report failed to come up with effective measures to keep the Rt at 0.75 in response to the highly contagious virus. Therefore, the golden balance put forward in the report is just a hallow theory. The report provides theoretical backing to the "Coexisting with COVID-19 Policy" adopted by European countries and the U.S., which was the scourge of later resurgence in those countries.

In fact, new infected cases in Europe have risen sharply since autumn. On Oct. 14, daily new cases increased to 105,000 in Europe, outnumbering Asia's 103,000. On Oct. 15, new cases of infections in Germany soared to 6,638 in the past 24 hours, reaching a daily level not seen since the start of the pandemic.

Report 9received a chorus of criticism in the U.K., because people worried about the impact of lockdown restrictions on economy. The report predicted the novel coronavirus would kill 510,000 people in the U.K., if mitigation measures were not in place. As a result of measures like restrictions, deaths in the U.K. had been capped under 43,000 by Oct. 11. Despite obvious effect, U.K. lockdown rules were lifted when there were still cases for fear of an economic downturn. The "Coexisting with COVID-19 Policy" led to a surge in infections in the U.K. in autumn, prompting London to upgrade its COVID alert level from medium to high on Oct. 15.

By May 11, 31,000 deaths had been caused by COVID-19 in Italy. However, the country lifted the two-month lockdown in early May to reopen its economy. As Chart 2 shows, in the five months from May 11 to Oct. 11, death rates in Italy dropped from 14% to 4%, meaning that Italy had survived from its medical care system collapse. But the pandemic returned in autumn, after the country adopted the "Coexisting with COVID-19 Policy". On Oct. 14, the number of daily new cases climbed to 7,300, the highest since the start of the outbreak in March. In response, Italy had to once again ban dining together, and order restaurants to close before midnight.

On Oct. 25, Spain announced the state of emergency and implemented a curfew to rein in the second outbreak. On Oct. 29, Spain's parliament voted to keep the country's state of emergency in place until May 2021.

The outbreak also resurged in France. On Oct. 14, French President Emmanuel Macron announced the 9 p.m. to 6 a.m. curfew starting Oct. 17 in nine cities including Paris and Marseille. On Oct .15, French Prime Minister Jean Castex declared a national state of health emergency starting Oct. 17. On the same day, France reported the number of new daily infections jumped above 30,000, setting a one-day record. On Oct. 30, France began its second nationwide lockdown. On Nov. 6, France registered a record 60,000 plus new cases, triggering more stringent restrictions.

U.S. President Donald Trump said long-term nationwide lockdown is not a solution. In late May, the Trump administration decided to restart economy in all states, regardless of the spreading virus. As case numbers rose sharply, New York had to announce a partial lockdown starting Oct. 4. From Nov. 4, daily new infection numbers in the U.S. kept above 100,000 for many days in a row, repeatedly setting new highs. On Nov. 7, the tally of confirmed cases surpassed 10 million in the U.S., and total deaths reached 242,339.

Those European countries, the U.S. and Japan, which adopted the "Coexisting with COVID-19 Policy", had to resort to lockdown measures to stop the spread of the virus.


Table 3 A projection and comparison of real GDP growth rates among countries and regions. Sources: the National Bureau of Statistics of China, the Cabinet Office of Japan, the Bureau of Economic Analysis of the U.S. Department of Commerce, the British Office for National Statistics, the Italian National Institute of Statistics, the Spanish National Statistics Institute, the Federal Statistics Office of Germany, the French National Institute of Statistics and Economic Studies, the Bank of Korea, the Directorate General of Budget, Accounting and Statistics of China's Taiwan, the Asian Development Bank and the International Monetary Fund.

The resurging virus in autumn and winter seasons posed daunting challenges to those countries that opted for the "Coexisting with COVID-19 Policy". Compared with them, China benefited from its "Zero COVID-19 Case Policy" as all localities across the country resumed economic activities and normal life based on their situations. After the postponed National People's Congress concluded on May 28, China basically resumed normal economic activities. During the National Day holiday, domestic tourists made 640 million trips. China's real GDP shrank by 6.8% in the first quarter from a year ago as the coronavirus outbreak seriously impacted its economy. China's real GDP grew by 3.2% in the second quarter, rebounding from the first quarter's contraction. The IMF projected that China's real GDP will grow by 1.9% in 2020.

The economy of Japan, European countries and the U.S., which adopted the "Coexisting with COVID-19 Policy", continued to shrink in the second quarter, widening their falls compared with the first quarter. Some countries even exhibited a negative double-digit growth. The IMF projected that those countries will all have a negative economic growth in 2020.

South Korea, Singapore, Vietnam, which experienced the test of the SARS outbreak like China, deployed the "Zero COVID-19 Case Policy". As shown in Chart 3, Vietnam and China's Taiwan have better economic performance. According to an IMF forecast, Vietnam's real GDP will grow by 1.6% in 2020, and the real GDP growth of Taiwan province of China will stand at zero. South Korea may see a 1.9% GDP contraction for 2020, which is a smaller drop compared with other Western countries. Singapore's economy, which is vulnerable to the world's economic fluctuations due to its heavy reliance on global trade, suffered a great slump in the second quarter.

According to the analysis above, compared with the "Zero COVID-19 Case Policy", the "Coexisting with COVID-19 Policy", which was intended to cushion the economic blow from a lockdown, turned out to be a failure that caused a long-term economic gloom.

By Nov. 8, there had been more than 50 million cases of infection globally. The winter outbreak would be worse, with the number of infections soaring. Europe and the U.S. have become the epicenter of the outbreak. I suggest that all countries around the world should take the "Zero COVID-19 Case Policy" when wonder drugs and efficient vaccines are not available, to contain the spread of the virus.

(4) Japan: Swinging between economic growth and COVID-19 response

Japan reported the first confirmed COVID-19 case on Jan. 16, 2020. The first flight of the Japanese government taking 206 Japanese citizens took off in Wuhan and bound for Japan on Jan. 29. On Feb. 13, Japan reported the first COVID-19 death. On Feb. 28, Hokkaido released its announcement of emergency. On March 13, the Diet, or the Japanese Parliament, passed an amendment of a special law to combat COVID-19, including the virus to the list of infectious diseases suitable for the law. The special law stipulates that the government is granted enhanced authority to declare a state of emergency in condition that the COVID-19 epidemic may threaten people's lives and inflict great losses on society, laying a legal basis for the government to declare a state of emergency.

The Japanese government declared a state of emergency on April 7 with respect to the seven prefectures: Tokyo, Kanagawa, Saitama, Chiba, Osaka, Hyogo, and Fukuoka. On April 16, the state of emergency was expanded to the whole nation. That was a loose requirement aimed at reducing person-to-person contact by at least 70% to 80%, rather than a lockdown targeting at no new local cases. Even so, as shown in Chart 4, the daily new confirmed COVID-19 cases in Japan plumped immediately, and the declaration of a state of emergency achieved remarkable results in disease prevention and control. As the situation improved, the Japanese government lifted its nationwide state of emergency on May 25. Different from China, Japan reported 20 new cases on that day. The lifting was accompanied by new confirmed cases.

China required that a place must report no new COVID-19 cases for 14 consecutive days before it announced itself to be a low-risk area, but Japan lifted the state of emergency with new cases, which boded that the epidemic may come once again. It turned out that a week after lifting the state, Tokyo had to declare its state of emergency due to the rapid increase of infections, so as to raise the people's awareness of disease prevention and control amid severe COVID-19 epidemic.

Since July 22, Japan started to carry out the "Go to Travel" campaign to revive tourism and stimulate economy in places except Tokyo. On that day, the new confirmed COVID-19 cases in Japan amounted to 792, 10% more than the peak number in the state of emergency, proving the move to be a temerity regardless of anything. Ten days later, the daily new cases surged to 1,575, a 120% increase over the peak number during the state of emergency.

On Oct. 1, Tokyo was involved into the "Go to Travel" campaign. The number of Tokyo's new cases reached 284, a rising trend again.

As shown in Table 2, by the end of Oct.11, Japan's death toll from COVID-19 of every 100,000 people is only 1.3, lower than 66.3 of the U.S., 63 of UK, 59.8 of Italy, 50.1 of France and 11.6 from Germany. In terms of fatality rate, Japan is the lowest among developed countries. It can be said that Japan suffered least of the countries adopting the "coexisting with COVID-19 policy". However, the winter when influenza virus may rage is coming soon. The flu virus and the COVID-19 virus would pose more challenges to Japan. Meanwhile, Japan's economy under the long period of "coexisting with COVID-19 policy" has been fettered and sluggish. As shown in Table 3, IMF estimated that the real GDP of Japan may decrease 5.3% in 2020.


Chart 4: Numbers of daily new confirmed COVID-19 cases and deaths in Japan Sources: Database of positive cases of the Ministry of Health, Labor and Welfare of Japan, and NHK's special website for COVID-19 deaths in Japan.

5. 'Jared M. Diamond Hypothesis' VS 'Zhou Muzhi Hypothesis'

There had been 1.5 COVID-19 deaths among every 100,000 Japanese by Nov. 11, 2020. This was a "slight" death rate compared with Spain's 58.8, the U.S.' 74.6, the U.K.'s 74, Italy's 71.1, France's 65.1, and Germany's 14.1. The question is raised that how Japan managed to control its COVID deaths at such a low level, while implementing the "Coexisting with COVID-19 Policy" that European countries and the U.S. all deployed.

Among all speculations trying to explain Japan's low death level, I think "cross-immunity" is the most compelling one. The theory opined that the immunity acquired by the Japanese people has played a role to some extent in preventing COVID-19 or mitigating its symptoms.

The question here is how Japanese people acquired cross-immunity against the novel coronavirus.

U.S. expert Jared M. Diamond hypothesized in his "Guns, Germs, and Steel: The Fates of Human Societies" that during the long time of close contact with poultry, European people became immune to many pathogenic bacteria. On the contrary, as Americas had no domesticated poultry, native people there lacked immunity to bacteria. The European people brought bacteria to Americas in the age of great navigation. The bacteria wreaked havoc on natives who lacked immunity, wiping out population[19].

I agree with Jared M. Diamond's hypothesis that Europeans obtained immunity from their long-time close contact with poultry. However, the hypothesis failed to explain why European countries were greatly eclipsed by Japan in terms of the number of COVID-19 deaths, despite of the fact they are all in Eurasia. What's more, besides Japan, other East Asian countries, including China, all reported smaller numbers of COVID-19 deaths

By Nov. 11, China, South Korea, China's Taiwan province and Hong Kong Special Administrative Region, Vietnam, and Thailand registered 0.3, 0.9, 0.03, 1.4, 0.04 and 0.09 COVID-19 deaths per 100,000 people, respectively, "very minor" compared with European countries rich in medical resources. Such relatively good performances, though largely due to the "Zero COVID-19 Case Policy", have also benefited from cross immunity.

I hereby put forward a hypothesis that the lifestyle centering on rice fields in humid regions of East Asia plays a determining role in people's acquisition of cross immunity against the novel coronavirus. The "Zhou Muzhi Hypothesis" is detailed as follows: The humid rice-growing Satoyama boasts rich ecological diversity, and a new ecology formed upon a moderate intervention of human beings in nature, one with richer diversity than primitive natural ecology. The diversity is also reflected in microorganisms. In Satoyama, human beings, nature, and poultry are in close contact and influence each other, shaping a huge breeding spot for pathogens. This place is richer in microorganism diversity than Europe, though they both belong to Eurasia. Therefore, I infer that people living in rice-growing regions with a variety of pathogens have stronger cross immunity [20].

Studies on cross immunity against novel coronavirus are still in their infancy. The recent research findings published by Manish Sagar of Boston University confirmed that people who have been infected with seasonal coronaviruses can develop cross immunity against novel coronavirus, thus alleviating severe symptoms[21].

Tatsuhiko Kodama from the Isotope Science Center at the University of Tokyo found through an analysis of the blood of 50 COVID-19 patients in Japan that 75% of the patients have cross immunity against the novel coronavirus[22].

In fact, seasonal coronaviruses have been frequently around in the humid regions of East Asia. If they can help people develop cross immunity against the novel coronavirus, it should be a grace of living in the rice-growing Satoyama.

From this perspective, it is important and worthwhile to think how to evaluate the life in Satoyama where people and nature influence each other, and how to draw on experience from Satoyama lifestyle in our modern life.

6. From global failure to global fight

Infectious diseases were once the most vicious killer of human. For example, the Black Death broke out in 1347 in Sicily caused the death of 25 million people in 20 years. The Spanish flu that broke out in 1918 killed 25 to 40 million people worldwide.

In the past century or so, with the development and popularization of antibacterial drugs and vaccines, most of the infectious diseases once extremely harmful to human health and life such as smallpox, polio, measles, rubella, mumps, tetanus, whooping cough, and diphtheria, have been extinct or under control. After the 1950s, the death toll in developed countries caused by infectious diseases such as pneumonia, gastroenteritis, hepatitis, tuberculosis, and influenza,, dropped sharply, while chronic diseases like cancer, cardiovascular and cerebrovascular diseases, hypertension, and diabetes have become the main causes of death.

The achievements made in the prevention and treatment of infectious diseases have increased the average life expectancy of human beings, but the alternation of the main death causes has also shifted the focus of the global medical systems, especially those in developed countries, from infectious diseases to chronic diseases. The consequences are that countries now invest little resources in the prevention and treatment of infectious diseases, and meanwhile, existing medical resources are mainly concentrated on addressing structural problems of chronic diseases.

From the perspective of existing medical resources, neither the professional background of medical workers, the devices, nor the entire medical system can effectively respond to the outbreak in a timely and effective manner. Therefore, in the fight against the virus, even metropolises with huge medical resources, such as Wuhan, New York, and Tokyo, were caught off guard and paid a heavy price.

As early as in 2015, Bill Gates warned people that investing too little in viral infectious diseases would lead to a global failure. The scourge of the COVID-19 epidemic unfortunately confirmed Bill Gates' prediction.

7. Explosive technological progress

The current measures of various countries to combat COVID-19, such as national state of emergency, lockdowns of the country and cities, self-discipline when going out, and keeping social distancing, focus on reducing and cutting off people-to-people communication to block the spread of the virus. Although the measures have achieved certain results, they cannot eradicate the virus from the root. Though the epidemic has been controlled by the strong "Zero COVID-19 Case Policy", the achievements are very weak, and any slack or loophole may trigger a resurgence.

We must rely on the technological progress to return to a safe and secure world. At present, all countries are stepping up the research and development efforts to find wonder drugs and vaccines for COVID-19.

The pandemic has been inspiring the breakthroughs in related technologies. Human beings dare not to say that they have controlled and defeated the virus until they master effective testing methods, wonder drugs and vaccines.

Opportunities also lie in crises. Every global war and crisis in modern society has brought a major transformation and explosive technological progress to mankind. For example, the WWII stimulated the development of the aviation industry and initiated the nuclear industry. The Cold War not only promoted the development of aerospace technology, but also laid the foundation for internet technology. The pandemic not only inspired the breakthroughs of technology but also greatly promoted the digital transformation of human society.

While the tension brought by the pandemic is pushing forward technological progress, it may also explore new technological paths so that those overlooked in the past can stand out. For example, traditional Chinese medicine has played an excellent role in Wuhan's anti-epidemic process and won global attention. The fight against COVID-19 may become an important opportunity for traditional Chinese medicine to go global.

Ozone is also a technological option that has been neglected due to prejudice. As early as on Feb. 18, I wrote an article appealing for the attention to the performance of ozone in sterilization and advocated the use of ozone in the COVID-19 fight[23].

Experiments in Japan have proved that the possibility of virus transmission through droplets in a closed environment is 17.7 times more than that in a non-closed environment. Therefore, an important anti-epidemic measure of the Japanese government is to call on people to avoid going to confined spaces, densely populated places, and contacting each other closely. If we can make breakthroughs in the research and development of ozone sensors and control the ozone concentration as cheaply and freely like we did in temperature control, we are expected to solve the indoor virus infection problem in the presence of people by using ozone to sterilize and kill the virus, thus freeing people from the fear of contact. The globally concerted efforts in combating the pandemic will surely inspire huge technological progress and upgrade a large number of industries.

8. Globalization will not stop

Countries around the world have been cutting off international personnel exchanges and locking down cites since the global outbreak of COVID-19. Globalization has been instantly stopped. We are inundated with worries about globalization, and doubts and even opposition about metropolitanization.

Indeed, with the further development of globalization, international personnel exchanges have been expanded. The overseas trips worldwide have surged from 400 million 30 years ago to 1.4 billion in 2018.

Against the backdrop of globalization, metropolitanization is the extension of globalization. From 1980 to 2019, 117 cities around the world saw its population increase by more than 2.5 million people, and the increased population amounted to 630 million in total. Particularly, the number of megacities with a population of over 10 million surged to 33 from only five in 1980. And these megacities are mostly centers of international exchanges, and leaders in the world economic and political development. The population of those megacities amounts to over 570 million, accounting for 15.7% of global population.

The virus has been spread worldwide through the dense aviation network and a large number of international personnel exchanges, making COVID-19 a pandemic. Many international metropolises with large populations and extensive international exchanges have been severely stricken by it.

But it must be clear that the real reason for global spread of COVID-19 is not the speed and density of international personnel exchanges, but the long existing neglect towards infectious diseases among human beings.

Actually, the progress of globalization has been accompanied by the threat of spreading infectious diseases from the very beginning. From the Age of Navigation to today, human beings have been fighting against infectious diseases and paid heavy price many times during the period. But due to the achievements in suppressing infectious diseases, many countries and international organizations tended to underrate their threat.

For example, the Global Risks Report 2020 released at the World Economic Forum listed 10 possible global risks for the future 10 years and infectious diseases were not included. In the list of the ten risks of the greatest global impact, infectious diseases only ranked the last.

Unfortunately, contrary to the prediction of the World Economic Forum, the COVID-19 pandemic brought unprecedented blows to human society at the beginning of 2020.

Most countries and regions that once experienced SARS, such as China, Singapore, South Korea, and Vietnam, have responded with measures similar to the "Zero COVID-19 Case Policy" and achieved good effects. That is probably thanks to the impressive experience of combating SARS. China has incorporated the experience of combating SARS into laws, regulations and general emergency response plans, and compiled related measures into manuals and guidebooks, which determined a quick launch of effective measures in time amid the COVID-19 outbreak and suppressed the epidemic[24].

In this sense, we do not need to be pessimistic. COVID-19 has drawn global attention and led to global investment in viral infectious diseases, which will definitely trigger an explosive technological revolution and social change. We will eventually overcome the threat from viral infectious diseases and turn the global failure to a global victory.

The pandemic will not stop globalization and international metropolitanization, but give birth to a better globalization and healthier international metropolises after pains and sufferings.

(Kurimoto Kenichi, Zhen Xuehua, and Zhao Jian contributed to data compilation and graphic production in the article.Wen Feng contributed to proofreading.)


1. Zhou Muzhi, "COVID-19: Why is the medical system in metropolises so vulnerable?" In China.com.cn, Apr. 20, 2020 (http://www.china.com.cn/opinion/think/2020-04/17/content_75944655.htm)

2. Zhou Muzhi, "COVID-19: Why is the medical system in metropolises so vulnerable?" In China.org.cn, Apr. 21, 2020 (http://www.china.org.cn/opinion/2020-04/21/content_75957964.htm?from=singlemessage&isappinstalled=0).

3. Zhou Muzhi, "COVID-19: Why is the medical system in metropolises so vulnerable?" In Japanese.China.org.cn, Apr. 21, 2020 (http://www.china.org.cn/opinion/2020-04/21/content_75957964.htm?from=singlemessage&isappinstalled=0).

4. For information about China Integrated City Index, please refer to 2018 China Integrated City Index: Development Strategy of megalopolises issued by the People's Publishing House in September 2019.

5. There was no COVID-19 death in Wuhan after May 11, 2020.

6. Japan successfully avoided overloaded medical system as COVID-19 testing in the country can only be done after the person has gained a testing approval after medical consultations. However, limited testing has caused delayed quarantine of asymptomatic and moderate cases. Moreover, medical consultations and approval procedures before the testing also increased the work load of medical facilities.

7. A dinner party attended by 40 trainee doctors from Keio University has caused 18 people tested positive for COVID-19 in March even after the Japanese and Tokyo governments issued guidelines against mass dinner gatherings.

8. According to information published by ICN on Sept.16, nearly 3 million health care workers were infected by the novel coronavirus by Aug. 14 from data provided by 33 nurse organizations of 32 countries. For more information, please visit https://www.icn.ch/news/new-icn-report-shows-governments-are-failing-prioritize-nurses-number-confirmed-covid-19-nurse.

9. For details, please refer to the Emergency Notice of the Ministry of Transport on Effectively Preventing and Controlling the Epidemic through Traffic Control in and out of Wuhan on Jan. 23, 2020.

10. The Response Plan for Public Health Emergencies in Hubei province was deliberated and approved at the 52nd executive meeting of Hubei provincial government on Apr. 22, 2010. It is formulated in accordance with the Emergency Response Law of the People's Republic of China, the Law of the People's Republic of China on Prevention and Treatment of Infectious Diseases, the Food Safety Law of the People's Republic of China, the Law of the People's Republic of China on the Prevention and Treatment of Occupational Diseases, the Frontier Health and Quarantine Law of the People's Republic of China, the Regulation on the Urgent Handling of Public Health Emergencies, the National Response Plan for Public Health Emergencies, and the Overall Response Plan for Emergencies in Hubei Province.

11. Responses to major public health emergencies are divided into four levels. The implementation of the first-level response requires to be organized by the State Council or the health authorities and other relevant departments under it. For details, please refer to the National Response Plan for Public Health Emergencies.

12. The Chinese government promulgated the Regulation on the Urgent Handling of Public Health Emergencies, on May 7, 2003, and the National Response Plan for Public Health Emergencies on Jan. 8, 2006, based on the experience of combating SARS and in accordance with the Law of the People's Republic of China on Prevention and Treatment of Infectious Diseases (coming into force as of Sept. 1, 1989). The National Response Plan for Public Emergencies was formulated based on the aforementioned law, regulation and overall plan. On Aug. 30, 2007, the Standing Committee of the National People's Congress approved the Emergency Response Law of the People's Republic of China, further systemizing the above-mentioned law, regulation and response plans. On Jan. 20, days before the lockdown of Wuhan, the National Health Commission issued its No. 1 announcement of 2020, categorizing the novel coronavirus pneumonia into the Class B infectious diseases stipulated in the Law of the People's Republic of China on Prevention and Treatment of Infectious Diseases, and adopting prevention and control measures for Class A infectious diseases.

13. U.S. President Trump deployed the USNS Mercy and USNS Comfort to Los Angeles and New York respectively in late March 2020. Both hospital ships have 1,000 hospital beds. Although they are not suitable for patients infected with the novel coronavirus, they can accommodate a large number of patients with common diseases, so that local medical facilities can free up more beds for patients infected with the novel coronavirus.

14. For details, please refer to Ferguson NM, Laydon D, Nedjati-Gilani G, et al., "Report 9: Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand", in Imperial College London HP , March 16, 2020.(http://hdl.handle.net/10044/1/77482)

15. On March 16, the White House issued the coronavirus guidelines, calling on Americans to practice social distancing; avoid gatherings of more than 10 people; avoid eating and drinking in bars, restaurants, and public food courts; avoid unnecessary trips, shopping or social activities; avoid going to sanatoriums, old people's homes; encouraging schooling from home across the country. On March 29, Trump extended the federal social distancing guidelines, which originally expired on March 30, to April 30.

16. For details, please refer to Solomon Hsiang, Daniel Allen, Sébastien Annan-Phan, Kendon Bell, Ian Bolliger, Trinetta Chong, Hannah Druckenmiller, Luna Yue Huang, Andrew Hultgren, Emma Krasovich, Peiley Lau, Jaecheol Lee, Esther Rolf, Jeanette Tseng & Tiffany Wu, "The effect of large-scale anti-contagion policies on the COVID-19 pandemic", in Nature, June 8, 2020.

17. On Feb. 17, 2020, the Joint Prevention and Control Mechanism of the State Council issued guidelines on taking science-based, targeted, region-specific, and multi-level measures on the epidemic prevention and control. The guidelines ordered governments at provincial levels to make dynamic adjustments to the list of high-risk, medium-risk and low-risk areas in their jurisdictions. According to the risk criteria defined in the guidelines, cities, counties and districts with no new confirmed cases?in the last 14 days are categorized as low-risk areas. Those with fewer than 50 cases or those with over 50 but without a concentrated outbreak are classified as medium-risk areas, and those with over 50 cases as well as a concentrated outbreak are classified as high-risk areas.

18. Wohlrabe Klaus, Peichl Andreas, Link Sebastian ,Leiss Felix, Demmelhuber Katrin, "Die Auswirkungen der Coronakrise auf die deutsche Wirtschaft", in ifo Schnelldienst Digital, No.7, May18, 2020.

19. Jared M. Diamond, "Guns, Germs, and Steel: The Fates of Human Societies", W.W. Norton, New York, 1997。

20. "Zhou Muzhi Hypothesis"was firstly published the seminar to commemorate the 120th anniversary of Tokyo Keizai University on Nov.21, 2020.

21. Manish Sagar, Katherine Reifler, Michael Rossi, Nancy S. Miller, Pranay Sinha, Laura White, and Joseph P. Mizgerd, "Recent endemic coronavirus infection is associated with less severe COVID-19", in Journal of Clinical Investigation, 30 Sep 2020.

22. Homepage of the Isotope Science Center of the University of Tokyo, July 16, 2020(https://www.ric.u-tokyo.ac.jp/topics/2020/ig-20200716_1.pdf)

23.Zhou Muzhi, "Ozone: a powerful weapon to combat COVID-19 outbreak" In China.org.cn, Feb. 26, 2020.(http://www.china.org.cn/opinion/2020-02/26/content_75747237.htm)

24. China has turned the experience in combating SARS into laws, regulations, manuals and guidebooks and those are the keys to combating the epidemic. On the contrary, in the U.S., Centers for Disease Control and Prevention prepared a guideline for restarting world economic activities, only to be rejected by the Trump administration in the first 10 days of May for being too detailed.