What can the world learn from China’s “zero-Covid” lockdown?

Short-term lockdowns could be key to ending pandemics early.

For the first time in three years, millions traveled within China earlier this month to reunite with loved ones for the country’s most important holiday, the Lunar New Year. Unfortunately, these celebrations coincided with — and are sure to exacerbate — a Covid-19 outbreak currently spreading throughout the country.

This spike comes on the heels of China’s National Health Commission ending many of its “zero-Covid” policies in December. These public health regulations had heavily restricted travel within and to the country, quarantined infected individuals in government-run facilities, and enforced city-wide lockdowns that required millions to stay indoors for months at a time. While the US threw the term “lockdown” around in the early stages of the pandemic, China was one of the few countries that actually did lock down its population.

These initiatives did prevent repeated surges in Covid-19 cases. But it also led to inadequate responses to other health crises and emergencies — including a November 2022 building fire in the Xinjiang region where virus-related blockades prevented an effective emergency response. Protests over the last few months of 2022 bubbled across major cities like Shanghai, Beijing, and Urumqi, calling for an end to lockdowns, censorship, and in some cases, even Chinese leader Xi Jinping’s presidency.

Beijing’s decision to end zero-Covid policies may have saved the nation from further social chaos. But how it eased up resulted in a public health crisis, with an estimated 2.02 million government-confirmed Covid-19 cases (though that’s likely an undercount) as of January 29, compared to 119,836 cumulative cases a year ago.

Although a variety of zero-Covid strategies have been tried in different countries since the start of the pandemic, they have varied in intensity, length, goals, and outcomes. In some nations, lockdowns were used intermittently to control outbreaks and to give public health leaders time to develop and distribute vaccinations. China’s lockdowns were used as a primary prevention measure. Partially, China’s current outbreak stems from the country’s all-or-nothing mentality, experts told Vox. The country eased lockdowns, travel restrictions, and mass testing, all at once — and the virus came rushing in.

Lockdowns aren’t a popular public health strategy when strung out for long periods of time. But that doesn’t mean they can’t be a useful option in the pandemic playbook. Lockdowns cannot contain a disease like Covid-19 indefinitely — especially more contagious variants — but they can mitigate the spread and give public health leaders time to prepare for other aspects of their pandemic response, such as vaccinations. The public health lessons learned from the end of China’s zero-Covid era might be some of the most important in preparing for future pandemics and learning how to live with diseases.

“At the beginning [of a pandemic], if there’s no treatment, no vaccine, and we have very limited knowledge about this new phenomena, a lockdown is more acceptable,” said Jennifer Bouey, chair of the global health department at Georgetown University. “Once there are vaccines, once there’s treatment, once we understand the nature of the pathogen, then they should be switched to a combination of different things.”

Lockdowns worked during SARS. China hoped they would work again.

In January 2020, only two days before the Lunar New Year, China banned travel to and from the 11 million-person city of Wuhan because of the newly discovered SARS-CoV-2 virus, soon known as Covid-19. In March, as the threat of the virus grew, other countries closed their borders, with the World Health Organization declaring Covid-19 a pandemic.

Many countries, including China, adopted true lockdowns as a means to stamp out the Covid-19 virus. These measures quarantined infected and exposed individuals, and locked down entire buildings, cities, and regions.

China had reason to believe this strategy would work again, given that during the outbreak of SARS — now called the SARS-CoV-1 virus — in the early 2000s, the nation used a citywide lockdown of Beijing in 2003 to contain the disease. “People didn’t go out for six weeks, school was canceled, the streets were empty, and the epidemic ended,” said Elanah Uretsky, chair of international and global studies at Brandeis University, of China’s SARS response. “It ended because of those lockdowns and massive quarantine policies. And we learned to believe in them.”

In the first year of the Covid-19 pandemic, little was known about how the virus spread, so public health guidance changed constantly. The application and length of lockdowns varied by country. In France, there were clear guidelines that allowed residents to travel outdoors for activities such as walking a pet. In contrast, in Wuhan, only one member of a household was permitted outside every two days to buy necessary resources. New Zealand, an island country with a zero-Covid approach, prevented Covid cases and deaths early in the pandemic by closing its borders.

However, Covid-19 proved to be more “elusive” than SARS, said Uretsky. Covid can present asymptomatically — unlike SARS — and therefore it can evade some contact tracing protocols. While it isn’t as deadly as SARS, Covid is more transmissible, meaning that one person infects multiple people at a higher rate.

Meanwhile, it was difficult for countries with large populations and land masses, such as the US and China, to have the type of nationally coordinated response seen in smaller island nations like Singapore and New Zealand. Given its size and politics, the US was unable to nationally coordinate the country’s Covid response and instead relied on individual regions or states to dictate public health measures.

Instead of zero-Covid, the US opted for a strategy of “flattening the curve,” which entailed decelerating the rate of Covid-19 infection to ease the burden on hospitals. “I think China’s massive error, considering that their population is enormous, was not doing what many countries did, or strived to do, which was ‘flatten the curve,’” said Maureen Miller, an epidemiologist with the Mailman School of Public Health at Columbia University.

In mid-2021, even nations that had maintained low case numbers and death rates through lockdowns adjusted their policies, and instead focused on vaccination campaigns and ramping up contact tracing efforts. Wealthy nations with access to vaccines began immunizing their populations in December 2020, and by the end of August 2021, over 2 billion people were fully vaccinated. Over the last year and a half, many former zero-Covid countries prioritized administering booster vaccines and slowly phased out contact tracing protocols.

Li Zhihua/China News Service via Getty Images

Meanwhile, in China, the nation’s zero-Covid policies dragged on for two years. The nation was able to keep cases low, relative to its population, until March 2022. At that time, the omicron variant of the virus swept through the country, leading to a lockdown in the 25 million-person city of Shanghai for two months. This extended lockdown sparked anger among residents and would add fuel to the growing anti-government sentiments that manifested via protests later that year.

Why China’s post-zero-Covid era is going so poorly

After over 150 partial and full city-wide lockdowns and months-long protests, China released new Covid-19 guidelines in early November and early December that softened or reversed earlier zero-Covid practices. In November, the guidelines cut down isolation time, removed mass testing sites, and increased resources to health care facilities. In December, health codes (proving lack of Covid exposure or a negative test result) to enter most public spaces were no longer required and infected individuals with mild or no symptoms could quarantine at home rather than at government-run facilities.

However, China lifted these policies not because it was prepared to do so, but because of political pressure from the nationwide protests, said Ha-Linh Quach, a research assistant at Duke NUS medical school in Singapore. Quach — who also previously worked with Vietnam’s National Committee of Covid-19 — said Vietnam followed China’s lead when attempting to manage the spread of the virus, but also found that mass quarantines were publicly unpopular. Instead, in 2021 the country began prioritizing social distancing, mask-wearing policies, and vaccine distribution.

Unlike other countries — like Taiwan, South Korea, or Singapore — that used periods of strict lockdowns to prepare for their inevitable reopening, and the internal travel that it would spawn, China did no such thing, said Uretsky.

Rather than reopening in stages, China lifted many of its most useful measures all at once — despite the fact that prior to easing these regulations, Covid cases were already on the rise. “Unfortunately for China, lack of preparation for the inevitable breach of an increasingly infectious pathogen results in exactly what we’re seeing,” said Miller.

For example, alongside these eased regulations, China announced it would ramp up its vaccination of the elderly, something the experts Vox spoke to say should have happened much earlier. When the restrictions were lifted, only 40 percent of Chinese residents above the age of 80 had received a Covid-19 booster shot, according to China’s National Health Commission.

Other countries that exited periods of intense lockdowns, such as Vietnam, not only used vaccines to prepare, but also bolstered their social distancing policies and contact tracing programs as they transitioned, said Quach.

As part of its zero-Covid policies, China used a digital health code system that assigned users QR codes based on their exposure and testing status, and that were needed to enter public spaces. Now, these codes are no longer required to access many public areas or to travel in China.

Yet Singapore, when the nation lifted many of its zero-Covid policies in June 2021, continued to use its version of these health codes for almost a year. These codes helped Singapore track down those who were exposed to someone with Covid-19 at an expedited rate. “It is not a breakthrough technology,” Quach said. “But it’s amazing to me how it is being used for public health.”

That said, these codes, while effective in the small nation of Singapore, had limited success in China due to the country’s size and lack of data-sharing. “On paper, it can work, but it’s very difficult to implement in the real world, especially in such a large country,” said Bouey. “It turns out that every province is doing their own work, and they’re not integrated. So when people travel from one province to another, the code suddenly doesn’t work.”

Lack of data and rampant misinformation have also exacerbated China’s post-lockdown problems. The current outbreak is thought to have begun in November 2022, and although the official number of total Covid-19 deaths in China, as of January 30, is now over 110,000 — which would still be low relative to the nation’s 1.4 billion population — the true figures are thought to be much higher. One model from December predicted that as many as 1 million people could die from Covid in China over the first few months of the year, but without transparent information from Beijing, these forecasts remain speculative.

“In the absence of data, there is misinformation,” Miller said. “I think the seeds of the spread of Covid were already happening in China. But the information as to the extent of it and the location of it would have allowed people to make informed decisions. In the absence of that, people are making whatever decision they want to make.”

What this teaches us for the next pandemic

Assuming another unknown virus will spread across the globe again in our lifetimes, the Covid-19 pandemic has given public health leaders fresh insight into what policies can be most effective in mitigating the spread of diseases. And lockdowns, when used appropriately and swiftly, remain a useful tool in our arsenal for early pandemic days.

Covid-19 was actually the “ideal candidate” for lockdowns, said Miller. This is because of the virus’s highly transmissible, airborne, and often asymptomatic nature. “Candidates for lockdown include pathogens that are novel to human populations, and therefore there is no innate immunity to them,” Miller said. “Highly infectious pathogens for which there are (currently) no vaccines or treatments are also candidates for lockdown.” In theory, the only type of diseases that lockdowns cannot mitigate are those that are not transmitted via human-to-human contact, such as water or foodborne illnesses, said Bouey.

Lockdowns give leaders time to develop vaccination distribution campaigns, set up contact tracing programs, and learn more about the pandemic-causing disease, Miller added.

This is why it’s important to distinguish between “short-term lockdowns with underlying goals” and “long-term lockdowns that hope to beat the odds and keep Covid out indefinitely,” said Miller. Brief lockdowns that helped “flatten the curve” were effective and helped keep hospitalizations and deaths down. But extended lockdowns, like the ones seen in China, failed to contain the virus and damaged the country’s economy and well-being.

“As we have seen, these lockdowns are very disruptive, in terms of economic livelihood, as well as social life and even mental health,” said Bouey. “There is profound damage to the society and to the economy.”