China had been thumped by its largest outbreaks of COVID-19 driven by The Sars-Cov-2 The Omicron BA.2 subvariant3 since the beginning of March 2022, bringing 176,558 infected people (by 5th March) in all 31 provinces, including over 100 cities in 36 days (hereafter also called the March outbreaks), with the latest daily infected new cases up to 20,000. Among 10 cities with over 900 infected cases, three of them were the most critical, including Changchun, Jilin and Shanghai (which alone had 90,600 people to be infected) (Fig. 1).
China’s “dynamic zero-COVID policy” had been working well and had successfully reached its goal of zero clearing each active chain of transmission, even during the period of the 5th wave driven by Omicron in the world4, until the March outbreaks. The outbreaks in Shanghai were considered as a failure of “dynamic zero-COVID policy”. The rapid epidemic expansion of the March outbreaks have plunged tens of millions of people into lockdown (Lewis, 2022), though all cities except Shenzhen did not implement the whole territory lockdown for one week. President Xi Jinping announced on 19th March 2022 that China would stick to its “dynamic zero-COVID policy”. This policy now stands in contrast to a global trend towards easing restrictions and attempting to co-exist with the circulating virus (Lewis, 2022).
But pervasive doubts about the present policy arose reasonably across the world including China’s own people. People were shocked by the fast climbing of the number of daily infected new cases as well as the extremely high percentage of asymptomatic cases, meaning the huge drop of the harmfulness of the virus in comparison with variants and subvariants before. Nationwide daily percentage of mild cases and severe cases were not openly published except Jilin Province. In Jilin, among all the infected cases, 99.56% were asymptomatic or mild, 0.42% were moderate and 0.07% were severe or critical. The nationwide number of severe cases remained in hospital were from 50 to 75 from 23th March to 5rd April 2022 indicating a very low percentage of the severe cases too. The percentage of the remained severe cases in the remained confirmed cases is 0.31% on 5rd April. Fatality rate was extremely low and 2 deaths were reported by Jilin on 18th March 2022 (case fatality rate of 0.0011% by far). The above-mentioned data tells why people began to doubt about the present policy.
Facing such a low severity rate or fatality rate, why China still adheres to its “dynamic zero-COVID policy”? Although vaccines could not protect people from contracting the Sars-Cov-2 virus, but scientists said that full vaccination could protect against severe disease and death, with higher effectiveness among adults ≥60 years5. There were sayings of low rates of full vaccination of elderly people in China, but that was not true. As press conferences of the Department of State reported, over 87% of the population was fully vaccinated by mid-February 2022. The full vaccination rate is 87.45% overall by 05 February and 87.77% by 14 March 2022. This rate of full vaccination is 88.01% in the overall population by 24 March 2022, with 84.36% or 222.72 million of those aged 60 and above. A total of 138.24 million (or 52.36% of) people over 60 years old received boost shots. China’s 7th census published its population as 1.412 billion, among them 264 million or 18.70% aged 60 or above6.
Our recent studies disclosed the essential reasons why China has been and will be adhering to its “dynamic zero-COVID policy”, including the choice uniqueness, morbidity differences in different cities, unpredictability, worries of sudden impact to medical system, successful zero clearing in some of the main cities and outstanding economy growth, etc.
Uniqueness of having a choice
Before March, Hong Kong had just recorded the most critical epidemics of in February with
close to 900 cases of COVID-19 per 100,000 residents in Hong Kong7, the highest level recorded anywhere in the world during the pandemic8. When its medical system was lashed breakdown by the epidemics, Hong Kong was unable to admit all COVID-19 patients who needed hospitalization. According to the press conference of HK SAR government, Hong Kong finally gave up mandatory PCR testing on 21st March 2022 it had no choice other than joining the global trend towards easing restrictions and attempting to co-exist with the circulating virus, at least in a quite long period of time from.
But China still has a Choice other than joining the global trend. Basically, it is a common sense for people to make their best choice when they have some different choices. So does a country. China was the only large economy who had controlled all transmissions of the Sars-Cov-2 virus before March, with only 2,873 confirmed cases remained, including 19 cases or critical. 155,729, the number of actual number of infected cases from 1st March to 3rd April 2022, was a tiny portion of the population, specifically as 1/9,000, indicating that the past month was just a very early stage of the March outbreaks.
Morbidity differences and unpredictability
There existed in different cities as many as twenty-time large differences in rate during the March outbreaks, revealed by an analysis of the full data in March. Omicron BA.2 subvariant is unpredictable of neither its transmission nor its morbidity rate and its virulence9. There had been obvious differences in morbidity rates between the 10 cities since the start of the March outbreaks. Their morbidity rates varied from 4% to 83%, with the lowest in Shanghai and the highest in Changchun, and 55% for the nationwide average except Shanghai , as shown in the follow figure. Additionally, the nationwide average rate is 37% (Fig. 2).
These obvious differences of morbidity rates indicate a difficulty in predicting the outcome of new outbreaks. And Morbidity rate in a city did not fluctuate much during most of the outbreak days. Take Shanghai as an example, rapid expansion of numbers of daily reported new infected cases rise sharply appeared, and the number reached over 20,000 per day within a period of 23 days, with a total actual number of 90,352 people to be infected on 31 March 2022. The morbidity rates of daily new cases in Shanghai ranged from 8% to 0% over 29 days of the whole month (36 days). The morbidity rate of total infected cases by far was 4%.
The reason why there were such differences is unknown. They were not related to any of the influence factors known today. There are two pairs of cities that can be compared since two cities of each pair are very close to each other, and both have the same climate, population density and characteristics, diet and living habits, religious background, education background and medical resources. Shenzhen and Dongguan, both adjacent to Hong Kong, are also adjacent. Both are located on the eastern bank of the Zhujiang Delta, which has a very high population density of 17 to 20 million people on approximately 100 square miles of land each. Being immigrant cities, the average ages of their population are relatively young, Shenzhen at 32.5 years and Dongguan at 34 years.
They have also had almost the same scale of circulation of people and cargo as Hong Kong. A large quantity of contaminated cargo and drivers arrived in Shenzhen and Dongguan with an unknown quantity of virus every day during the surge of infected cases of Omicron BA.2 in Hong Kong in the early stage of its COVID-19 outbreak in February 2022. When its medical system was lashed breakdown by the epidemic, Hong Kong was unable to admit all COVID-19 patients who needed hospitalization. People wished to escape from the outbreak. The border between Hong Kong and Shenzhen or Dongguan was strictly controlled to allow a certain limited number of passengers, which was approximately 10% of that in 2019. Illegal entries from Hong Kong to Shenzhen and Dongguan were reported as many dozens and were believed to be fact. Hide and seek follow-up to implement mandatory isolation and PCR tests. Outbreaks started from the end of February in both Shenzhen and Dongguan and resulted in 994 infected cases in Shenzhen and 1,314 infected cases in Dongguan in one month. Contradictory figures of the morbidity rate of the two cities appeared from the very beginning, starting from 100% to 92% in Shenzhen and 68% to 0% in Dongguan (Fig. 3). Each of these two outbreaks develops simultaneously on its own path of morbidity rate, and their rates seemed unlikely to change much until they were close to being controlled by stronger anti-epidemic measures. The difference in their final rates, which was 75% in Shenzhen and 12% in Dongguan, was still enormous. Their final morbidity rates were close to their initial rates, although daily rates may show strong fluctuation due to fewer daily new cases. One essential event was a whole area locking down in Shenzhen, including 11 districts, for one week starting from 14 March 2022, which was announced I the evening of 13 March 2022. On 18 March 2022, the Shenzhen authority canceled the lockdown of 5 districts with “zero active COVID-19 cases”. The final termination of the lockdown started at 00:00 on 21 March 2022.
Dongguan’s outbreak did not follow the expansion pattern of its neighbor Shenzhen, as shown the figures above. A similar pairs of cities are Changchun and Jilin, which are the first two large cities in Jilin Province in northeastern China and are approximately 111 kilometers apart, with a much larger scale of outbreaks reaching a total number of infected cases of 34,395 in Changchun and 27,878 in Jilin, with less than 985 cases of the confirmed cases converted from the asymptomatic cases. The outbreaks started in Jilin on 03 March 2022 and Changchun’s outbreaks followed one day after Jilin. Their morbidity rates also differed from the beginning, and their levels seemed steady, with Changchun’s approximately 85% and Jilin’s approximately 50%. Jilin’s number of daily new cases is declining steadily from its peak on 26 March 2022 while Changchun is on its platform. By far, the morbidity rates are 83% in Changchun and 54% in Jilin (Fig. 4).
Shanghai’s outbreak had a very slow start. But from 13 March on, the numbers of daily reported new infected cases rose sharply and reached 17,057, whereas a total of 90,000 people were infected, by 4th April 2022. The morbidity rates of daily new cases in Shanghai ranged from 8% to 0% over 28 days in the whole period of 35 days (Fig. 4). The morbidity rate of total infected cases by far was 4% (blue line, by 31st March as well as by 4th April). As a city with the most critical number of infected cases among the three (the other two are Chungchun and Jilin), Shanghai’s morbidity rate is the steadiest among all 10 cities with statistical significance.
Omicron BA.2 transmission unpredictable
The transmission of Omicron BA.2 is unpredictable, nor is its morbidity rate. Chinese cities are more like isolated islands than those of other countries because of strict prevention measures. This Omicron BA.2 subvariant seems to have developed a different pattern of virulence and transmission in these isolated cities of China. Among the ten cities with outbreaks in March, half had a very low morbidity rate, including Shanghai (4%), Langfang (8%), Binzhou (10%), Dongguan (12%) and Shengyang (18%). On the other hand, these five cities have a very high percentage of asymptomatic cases of infection, including Shanghai (96%), Langfang (92%), Binzhou (90%), Dongguan (88%) and Shengyang (82%). Two cities had high morbidity rates of infected cases: Shenzhen (75%) and Changchun (83%). All data were updated to 31 March 2022.
The severity rate and fatality rate are low. Nationwide data of China showed a percentage of 0.10% for the ratio of the severe cases to the confirmed cases in March. Jilin Province recorded 0.13% of the severs cases in the confirmed cases in the period off 1st March to 5th April. The fatality rate is less than 1/80,000, as 2 deaths were reported by Jilin on 18 March 2022.
Fewer cases needed hospitalization. Only Jilin Province published the data of the classifications of diagnosed COVID-19 patients daily. Jilin’s data showed that 99.14% of the infected cases were diagnosed as mild and 0.42% of the infected cases were diagnosed as moderate, and 0.07% were diagnosed as severe in Jilin Province. 0.49% of the total infected cases needed hospitalization according to the latest version the national Diagnosis and Treatment Protocol for COVID-19 Patients. Recovered cases returning to positive were not reported but were estimated to be approximately 1%, close to the figure announced by Shenzhen 3rd People’s Hospital on a news release in March 2022.
The ratios (possibilities) of the asymptomatic cases converting to the confirmed cases were 4%, 1.6%, 0.3% and 4.12%, respectively, in Jilin Province, nationwide excluding Shanghai, Shanghai and nationwide including Shanghai, from 1st March to 5th April.
Worries of sudden impact to medical system
The data in Jilin Province showed 0.49% of the infected cases needed hospitalization (following guidance of the national Diagnosis and Treatment Protocol for COVID-19 Patients10), including 0.07% of severe or critical cases. The Chinese version of the national Diagnosis and Treatment Protocol for COVID-19 Patients (Tentative 9th Edition) was published on 19th March 2022. Its English version has not been published yet. There is obvious difference in “Chapter XI Treatment” between the 9th edition and the 8th11. The symptomatic and mild cases will not be treated in designated hospitals according to the 9th edition.
According to the data published by press conferences of the government of China and Hong Kong Administrative Region, there were 6.4 hospital beds per 1,000 persons in China and 5.5 in Hong Kong. The medical system of Hong Kong was lashed breakdown by the outbreak of Omicron BA.2 in February. There would be no reason to be believed that China can avoid the breakdown of its medical system.
Scientists say the ratio of the critical patients in total number of the severe patients is as high as 35 to 50 in Jilin Province. Since there are only estimated basic reproduction number (R0) of Omicron BA.2 ( which might be up to 10 as some scientists indicted), the estimation of the need of hospital beds relies on the support of the sample survey in HK which indicated a minimum of 60% of the population to be infected in 50 days. According to such data and the data in this article, the number of hospital beds China might need is 4,150,000 in 50 days of easing restrictions, under the circumstances that the Omicron BA.2 keeps steady in morbidity rate with the present trend, which is denied by the present data. And if nationwide outbreaks follow the trend in Jilin Province in the future, a total number of 620,800 patients might be severe or up, including 434,600 of critical patients in 50 days. It will definitely thump the medical system into breakdown.
Successful zero clearing in some of the main cities
Among the 10 cities of rapid expansion during the March outbreaks, 5 of them have zero-cleared their daily infected new cases by far, as shown in the following figure, and they are Shenzhen, Dongguan, Qindao, Binzhou and Langfang. Their successful experiences give a full confidence to the nation as well as the cities with the most critical situation, such as Shanghai, Changchun and Jilin.
The following figure shows all the provinces (a total of 26) that had daily new cases on 5th April 2022. We can see clearly Shanghai and Jilin Province are the only two provinces that have been mostly stressed in their battle with the outbreaks. On the day, Shanghai reported 16,766 asymptomatic cases and 311 confirmed cases, whereas Jilin Province reported 1,798 and 973 accordingly. No other provinces reported daily cases more than 109.
Outstanding economy growth
It’s easy for people to get a conclusion that China’s “dynamic zero-COVID policy” is tremendously costly. Such conclusion locks support of data. Data shows that the better a country minimized its COVID-19 epidemics, the better economy growth they could achieve. The GDP growth rate of USA was -3.5% in 2020 (5.7% in 2021) while that of China was 2.3% (7.9% in 2021)12. USA’s CPI rose 4.8% in 2020 (7% in 2021) while China’s CPI rose 2.5% in 2020 (0.9% in 2021), meaning a much higher inflation in USA.
In much the Bureau of Statistics of China announced that China’s economy recovered better than expectation in the first two months of 202213. I do not see the reason why China should give up its “dynamic zero-COVID policy”.
Calculation of economy lost
There could not be many people who don’t agree on that all provinces can control their outbreaks except Shanghai and Jilin, since no province other than Shanghai and Jilin reported more than 109 infected cases on 5th April 2022, a figure which could be considered to be easy to control the outbreaks.
A hypothetical calculation based on the worst scenario of full lockdown in Shanghai, Changchun and Jilin city for 20 days. The national portion of economy of Shanghai, Changchun and Jilin are 3.78%, 0.62% and 0.14%, calculated with the data published by the press conference of the National Bureau of China. Suppose that they production are zero, which is impossible, during the lockdown, the daily economy loss of Shanghai, Changchun and Jilin will be 1.8 billion, o.3 billion and 0.066 billion US dollars (at an exchange rate of 1 dollar to 6.4 RMB), and the three cities will loss 43.32 billion dollars during twenty days, which is a portion of 0.02425% of China’s GDP in 2021.