- A commercial flight from Russia in July 2021 may have introduced the highly contagious Delta variant of the virus into China.
- By the beginning of August, at least 15 out of 31 provinces on the Chinese mainland have reported COVID-19 cases.
- In 2020, China’s policy of “zero tolerance” towards COVID-19 swiftly brought the world’s first outbreak under control within the country’s borders.
- However, it remains uncertain whether the same strategy will work against the more infectious Delta variant, while there are concerns about the levels of protection that Chinese vaccines provide.
On July 28, 2021, Ma Xiaowei, the minister in charge of China’s National Health Commission, declared that his country had brought the first outbreak of COVID-19 under control within 3 months.
In a meeting with the health ministers from BRICS (Brazil, Russia, India, China, and South Africa) and other global health officials, Ma Xiaowei said that China was the only major economy in the world to achieve growth in 2020.
As the pandemic that began in Wuhan in December 2019 spread around the globe, China reduced new infections close to zero by enforcing some of the most restrictive lockdown measures seen anywhere in the world.
A week before the BRICS meeting, however, this policy of “zero tolerance” was facing its most serious challenge after experts detected a new outbreak in the eastern city of Nanjing.
A commercial flight from Russia that landed in Nanjing on July 10 appears to have sparked the outbreak by introducing the highly infectious Delta variant into the country, according to Chinese authorities.
According to CNN, routine testing revealed SARS-CoV-2 infections in nine airport cleaners. Since then, at least 26 cities across China have reported cases of this variant.
Just a few weeks after the first cases in Nanjing, 15 out of 31 provinces on the Chinese mainland had reported SARS-CoV-2 infections.
In its daily briefing on August 9, 2021, the National Health Commission reported 125 new cases, 94 of them indigenous.
Delta variant steps up infection rates
Scientists first identified the Delta variant of SARS-CoV-2 in India in December 2020.
The variant has two key mutations in its spike proteins that allow it to cause infection in human cells much more easily, making it more transmissible.
The Centers for Disease Control and Prevention (CDC) report that the Delta variant is almost twice as contagious as previous variants.
Research suggests that, in unvaccinated individuals, the new variant may also be more likely to cause severe illness and hospitalization.
Worryingly, an outbreak in Provincetown, MA, in July 2021 suggests that vaccinated persons who contract infection with the Delta variant are just as infectious as unvaccinated cases.
The finding led the CDC to recommend that even fully vaccinated people wear masks in indoor public places in areas of substantial or high transmission.
Faced with an unexpected resurgence of the virus, authorities in China have persisted with their policy of zero tolerance through targeted lockdowns, contact tracing, and quarantining close contacts of individuals with the infection.
In Nanjing, for example, the entire population has undergone testing, while officials have locked down residential compounds with confirmed cases. All cinemas, gyms, bars, and libraries are closed.
Vaccines manufactured in China
In theory, China should be in a better position to contain the virus than in the early months of 2020, having administered more than 1.65 billion doses of vaccine.
But, as health authorities in the United States and elsewhere have discovered, vaccination provides less protection against the Delta variant.
CNN reports that the “vast majority” of people with a SARS-CoV-2 infection in the outbreak in Nanjing had already received their vaccination.
What’s more, there are concerns about the efficacy of China’s homegrown vaccines, Sinovac and Sinopharm.
The evidence of their efficacy against Delta is lacking from China itself due to relatively few cases. But in countries that China has supplied with its vaccines, such as Chile and Mongolia, cases are high compared with countries with similarly high vaccine coverage, such as Israel and the U.S.
Clinical trials suggest that Sinovac and Sinopharm, which manufacturers have based on inactivated viruses, are 50–79% effective at preventing infection. By contrast, Moderna and Pfizer-BioNTech, which are mRNA vaccines, confer more than 90% protection.
“Right now, what we can see very clearly is that the antibody level in people who received BioNTech is much higher — much, much higher — than the antibody level in people who received Sinovac,” Prof. Ben Cowling, head of epidemiology and biostatistics at the University of Hong Kong, told CNN.
That does not mean the Chinese vaccines are a failure, said Prof. Cowling. He explained:
“Somewhere like Chile, somewhere like Mongolia, vaccines have saved a lot of lives, but maybe they haven’t been able to stop the virus from spreading and causing mild infection in vaccinated people, and then, of course, the potential for more severe infection in people who haven’t yet been vaccinated.”
This means that even in areas where vaccine coverage is very high, they may not be sufficient to prevent the spread of the Delta variant.
On July 22, two days after the Nanjing cluster was first detected, a health expert in the city said the “vast majority” of individuals with a SARS-CoV-2 infection had undergone vaccination.
The limits of zero tolerance
This calls into question whether China’s policy of zero tolerance to COVID-19 can work against the highly infectious Delta variant.
Countries, such as Singapore and the United Kingdom, have adopted a more pragmatic attitude that many have referred to as “learning to live with the virus.”
This approach argues that societies must accept a steady rate of ongoing infections — most of them relatively mild as a result of vaccination — in order to sustain their economies and protect the well-being of the majority of citizens.
According to Vincent Ni, China affairs correspondent of the U.K.-based newspaper The Guardian, the Chinese virologist Dr. Zhang Wenhong, Ph.D. — popularly known as “China’s Dr. Fauci” — has said the outbreak in Nanjing should serve as “food for thought for the future of our pandemic response.”
Dr. Wenhong, who is head of the center of infectious diseases at Huashan Hospital of Fudan University, wrote in an essay:
“The data tell us that even if each of us were to be vaccinated in the future, COVID-19 would still be endemic, but at a lower level with a lower fatality rate. After the liberalization of vaccines, there will still be infections in the future.”
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