‘Zero COVID’ is getting harder—but China is sticking with it

As China battles its third major COVID-19 outbreak this year, the country is doubling down on the “zero COVID” strategy of mass testing, contact tracing, and containment that many of its Asian-Pacific neighbors have abandoned.

The flare-up of the highly infectious Delta variant, with more than 1000 cases reported since mid-October in 21 of the country’s 34 provinces and regions, has led China to take some extraordinary measures. Beijing residents who had the bad luck of traveling to what became COVID-19 hot spots were simply barred from returning home. On 31 October, after a single confirmed case was linked to Shanghai Disneyland, authorities tested 34,000 visitors to the park before allowing them to leave. Testing took until near midnight and turned up only negatives.

Such logistical challenges, increasing lockdown fatigue, and growing public opposition have led New Zealand, Singapore, and parts of Australia to give up on zero COVID, opening their economies and accepting a surge in cases that is small by international standards yet much bigger than anything they had seen before. But China intends to stay the course until vaccination rates—both at home and abroad—are so high that SARS-CoV-2 can do little damage.

“The current cost of adopting a ‘zero-transmission’ policy is indeed high, but it would cost even more if we live with [the virus] and open up,” Zhong Nanshan, a respiratory specialist at Guangzhou Medical University and China’s leading COVID-19 adviser, said in an early November interview with CGTN, a state-owned broadcaster.

China’s containment strategy “has been a great success in terms of minimizing the number of COVID-19 infections and deaths,” says Benjamin Cowling, an epidemiologist at the University of Hong Kong. China has only reported 127,018 cases of COVID-19 and 5697 deaths, according to the World Health Organization. The United States, with roughly one-quarter of China’s population, has seen 46.5 million cases and more than 750,000 deaths. But the success “comes at a great price in other areas,” says Dale Fisher, an infectious disease specialist at the National University of Singapore, including the economic and social toll. These include severe restrictions on international travel: Incoming tourism is barred, entry visas for other purposes are difficult to get, and travel abroad for Chinese is discouraged.

Experts outside the country are divided on whether it makes sense to continue the policy. Evolutionary virologist Edward Holmes of the University of Sydney says China is only putting off the inevitable. “I think China’s zero policy is completely unsustainable and ill-conceived for a virus that is obviously going to be endemic,” Holmes says. But Nick Wilson, a public health scientist at the University of Otago, Wellington, says sticking to zero COVID “might possibly still be the best strategy even at this stage—if it gives China time to increase vaccination coverage, including to children, deliver more booster doses, and allow time for improved vaccines to be developed.”

The increasing supply of vaccines, a desire to open borders, and the difficulty of stamping out Delta outbreaks led New Zealand to move from an elimination strategy to “suppression,” says Michael Baker, also a public health specialist at Otago. But the shift “involves complex trade-offs and considerable uncertainty,” he says.

Currently, more than 75% of Chinese adults are fully vaccinated, and even children as young as age 3 are now getting the shots, according to Caixin Global, a China-based news website. That is not nearly enough to keep the Delta variant at bay; even countries with vaccination rates higher than 85%, such as Singapore, are reporting substantial numbers of new infections.

George Gao, director of the Chinese Center for Disease Control and Prevention, predicts China will achieve 85% coverage early next year, but says “we are working very hard” to push the rate even higher. Booster shots will be rolled out in the first half of next year, Zhong told CGTN, which he said could help China reach herd immunity, a milestone that has proved elusive elsewhere. After that, China could relax its travel restrictions for countries with high vaccination rates, Zhong said—possibly by the end of 2022.

But the quarantine measures for visitors will likely stay in place, Cowling says. They are getting even stricter. Guangzhou, a booming metropolis near Hong Kong, just completed a 5000-room facility where incoming travelers—even the vaccinated—will have to spend 14 days of quarantine; previously they stayed at hotels scattered through the region. Other cities are building or planning similar facilities. Overseas travelers arriving in the northern city of Shenyang now face 1 month of hotel quarantine followed by another month of home confinement. In some cities, even domestic travelers from high-risk areas face quarantines.

In the end, vaccination may drive COVID-19 mortality down to match that of seasonal flu, which Zhong pegs at 0.1% to 0.5% in China. At that level, “we may be able to live with it,” he said. But not now, he cautioned: “China will still stick to the ‘zero-infection’ policy for a rather long time.”

With reporting by Bian Huihui.

source: sciencemag.org