Image source,Xinhua
Nanjing has launched the third round of nucleic acid testing.
The outbreak at Nanjing Lukou Airport in Jiangsu, China, caused by the 2019 novel coronavirus (COVID-19) variant Delta, has now spread to many provinces and cities across the country, and several second transmission chains have developed, including Zhangjiajie, Hunan. The public is worried that the “lost” of an airport will cause a new wave of national epidemics.
The National Health Commission of China updated on Thursday (July 29) that all provinces and municipalities in mainland China reported 49 new confirmed cases of new coronary pneumonia, of which 24 were local cases, and Jiangsu accounted for 20 cases. This also includes travelers suspected of being infected in Hunan and returning to Jiangsu.
The Nanjing epidemic prompted China to undergo stress testing, and it also posed challenges to the effectiveness of the Chinese-style “zero-diagnostic” epidemic prevention approach.
Chinese experts called for the public to accept coexistence with the new crown virus.
People with mild and asymptomatic infections
Nanjing Lukou Airport found nine positive cases during the regular nucleic acid inspection on July 20. In the past ten days, the epidemic spread to six provinces and 11 cities across China, including the capital Beijing, the northeast of Liaoning and the southwest of Sichuan. Both confirmed and infected persons were found in the central Hunan Province. The number of confirmed and infected people totaled about 200.
In this round of the epidemic, in the second-generation transmission chain of Lukou Airport, a large-scale performance in Zhangjiajie, Hunan Province on the 22nd became the focus of public concern. This is the intersection of the four asymptomatic infections in Liaoning on the space and time lines. More than 2,000 spectators participated in the performance, and all spectators belonged to high-risk groups.
Huai’an City, Jiangsu Province also confirmed on Thursday that four local tourists who went to Zhangjiajie, Hunan Province tested positive for the new coronavirus nucleic acid, and the Hongze District where three of them lived was immediately closed.
At present, most of the confirmed cases are mild and asymptomatic infections, and the transmission chain is still on the transmission line related to Nanjing Lukou Airport, and the cases are mainly concentrated in Nanjing.
Zhang Wenhong, director of the Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, posted on Weibo early on Thursday morning that the next one to two weeks is the key. If there are no more second and third generation cases in various provinces and cities, the scale of this round of epidemic will still be limited to Nanjing city.
This round of the epidemic originally originated from a cleaning staff at Nanjing Lukou Airport. It was suspected that there was a loophole in the outsourcing cleaning service at the airport, which led to the diagnosis of more than 60 related staff at the airport. Most of the confirmed people at Lukou Airport have been vaccinated against the new crown.
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Vaccines and mutant viruses
Among the confirmed cases in other provinces, there are also those who have been vaccinated. Zhang Wenhong said that someone can get infected after the vaccine. Like this time in Nanjing and the last time in Guangzhou, some people got infected after the vaccine. But if there is no vaccine, the number of people infected may be even higher. In the end, how effective the vaccine is, ultimately requires real-world prevention and control data.
There was a short-term epidemic in Guangdong Province in May, and the source was the variant virus Delta from India. Whether there are new changes in the variant virus at Nanjing Lukou Airport this time, further data and research are needed to explain.
According to statistics collected by the Public Health Service of Scotland and published in the authoritative medical journal “Lancet” (also translated “Needle”), the protection rate of Delta by Pfizer vaccine decreased at least two weeks after the second dose of vaccination. To 79%; and the protection rate of the Oxford AstraZeneca vaccine on Delta is 60%.
Shao Yiming, a researcher at the Chinese Center for Disease Control and Prevention, said on May 20 that preliminary research results show that Chinese vaccines “can deal with Indian variants and have a protective effect”, but China did not provide specific effective data.
Zhang Wenhong quoted an observation after the launch of an inactivated vaccine recently completed in Chile, saying that the results of Chilean vaccination show that China’s inactivated vaccine is highly effective in preventing the severity of the new crown, hospitalization and death. “If the goal is to slow down the spread and reduce the fatality rate, it can afford a certain degree of protection, but as the goal of clearing and eradicating the epidemic, it may be a goal that the current vaccine cannot achieve.”
Chile assessed the protection of the country’s mass vaccinations of Chinese inactivated vaccines from February 2 to May 1 this year. The cohort contains about 10.2 million Chilean populations. Among the population vaccinated with two doses, the Chinese inactivated vaccine:
- The effectiveness of preventing new crown infection is 65.9%
- The protection rate of preventing the hospitalization of patients is 87.5%
- The protective power to prevent ICU occupancy rate is 90.3%
- Protection against death is 86.3%
The new crown vaccine is the most effective in preventing death, the most serious consequence of infection, but it is not effective in preventing asymptomatic infections. According to the China National Health Commission’s Disease Prevention and Control Bureau, as of the 28th, China had received 1.601 billion doses of vaccines, and the proportion of the fully vaccinated population is unknown. At present, it is recognized that 70% of the population in the world can achieve herd immunity after receiving two doses of the vaccine, and then gradually return to normal life.
Coexisting with the virus The new crown becomes seasonal flu?
Zhang Wenhong did not mention the goal of “clearing to zero”. Instead, he believes that the continuation and recurrence of the epidemic will still not be fully controlled through vaccination in the future, but if the fatality rate drops to the level of influenza after full liberalization, the virus can be eliminated. The serious consequences of the epidemic, or the harm of the new crown through vaccination, will be reduced to the level of seasonal influenza through the establishment of population immunity in a short period of time.
This is also the first time that Chinese experts have voiced that through vaccination, epidemic prevention strategies can be changed, and the mortality rate of the new coronavirus can be reduced to the level of seasonal influenza.
Jin Dongyan, a virologist and professor in the Department of Biochemistry at the Li Ka-shing School of Medicine, University of Hong Kong, previously explained to the BBC that the new crown virus can be treated as a seasonal flu because the death rate of the new crown virus is comparable to that of seasonal flu. “Originally, the flu will also kill people. The death rate of the new crown virus was 0.48% before, and it is now 0.13%, while the severe flu death rate is 0.1%.”
Has China’s epidemic prevention strategy changed?
In 2020, China will take strict measures to close the city to physically cut off the spread of the new crown virus to effectively control the epidemic. After the outbreak of the Nanjing epidemic, many provinces and cities in China followed the previous prevention and control procedures to successively launch large-scale nucleic acid tests and close residential quarters.
Nanjing has carried out the third round of nucleic acid testing, and the city has actually been closed, and residents’ lives and work are restricted.
However, after the advent of the new crown vaccine, the uneven distribution of the global vaccine and the uneven vaccination rate are causing poor global immunity. Countries and regions that are the first to achieve herd immunity have begun to experiment with “vaccine passports”, hoping to achieve regional interoperability.
Due to the gap in economic strength, the vaccination progress of different countries is very different. This will also affect the global progress in overcoming the epidemic.
Most virologists around the world believe that the new coronavirus will be a resident virus, and the world must learn to coexist with it.
The vaccination rate in the UK has reached 70% of herd immunity. British Prime Minister Johnson announced the unblocking of Britain on July 19 amid repeated warnings from the scientific community. After unblocking, the number of confirmed cases in the UK has declined for six consecutive days, but the number of new cases has remained at 20,000 daily.
Zhang Wenhong said that how the world coexists with the virus, each country is making its own answer. China once gave a beautiful answer. After the Nanjing epidemic, we will definitely learn more.
The Nanjing epidemic is still going on. After this round of the epidemic is brought under control, will China change its epidemic prevention strategy and no longer regard “clearing” as an epidemic prevention goal, but learn to coexist with the virus? This is a concern of many people who are blocked by China’s strict isolation policy.