Vietnam defied the experts and sealed its border to keep Covid-19 out. It worked.

How the country has kept coronavirus deaths to just 35, and grew its economy in 2020.

HANOI — Every January or February, Le The Linh and his wife pack their children into their car and drive 80 miles to visit family in Haiphong, a port city east of the capital, for Lunar New Year. But this time, as they reached the last stretch of the Hanoi-Haiphong Highway, a police officer approached and pointed them toward a group of guards in face masks under a makeshift tent. It was one of 16 checkpoints erected around Haiphong to control travel into and out of the city ahead of the Tet Festival holiday.

The Linhs joined a lineup of other travelers, nervously waiting for their turn in the rain. When they reached the front, the officials asked for proof of their travel plans, residency, and Covid-19 status.

“Don’t worry!” Linh exclaimed tensely. He could show, with his identity card, that they lived in an area that had no coronavirus cases recently.

The Linhs were among the lucky ones let through. Travelers from areas near Haiphong who had recently recorded Covid-19 cases got turned away; a group of young people on motorbikes who tried to circumvent the checkpoint were arrested; still others chose not to travel at all, opting to meet family over FaceTime or Zalo (Vietnam’s answer to WhatsApp).

As the pandemic took hold last year, travel restrictions quickly proliferated — they were the second-most-common policy governments adopted to combat Covid-19. According to one review, never in recorded history has global travel been curbed in “such an extreme manner”: a reduction of approximately 65 percent in the first half of 2020. More than a year later, as countries experiment with vaccine passports, travel bubbles, and a new round of measures to keep virus variants at bay, a maze of confusing, ever-changing restrictions remains firmly in place.

But few countries have gone as far as Vietnam, a one-party communist state with a GDP per capita of $2,700. The Haiphong checkpoints timed for Tet were the equivalent of closing off Los Angeles to Americans ahead of Thanksgiving — within a country that was already nearly hermetically sealed. Last March, the government canceled all inbound commercial flights for months on end, making it almost impossible to fly in, even for Vietnamese residents.

Christina Animashaun/Vox

Today, flights are limited to select groups, like businesspeople or experts, from a few low-risk countries. Everybody who enters needs special government permission and must complete up to 21 days of state-monitored quarantine with PCR tests. (Positive cases are immediately isolated in hospital, regardless of disease severity.)

This strict approach to travel, global health experts say, is directly connected to Vietnam’s seeming defeat of Covid-19. Thirty-five people have reportedly died in total, and a little more than 2,700 have been infected with the virus during three small waves that have all been quickly quashed. Even on the worst days of the pandemic, the country of 97 million has never recorded more than 110 new cases — a tiny fraction of the 68,000 daily case high in the United Kingdom, which has a population one-third smaller than Vietnam, or the record 300,000-plus cases per day only the US and India managed to tally.

Last year, Vietnam’s economy even grew 2.9 percent, defying economists’ predictions and beating China to become the top performer in Asia.

Christina Animashaun/Vox

In this series, the Pandemic Playbook, Vox is exploring the Covid-19 strategies used by six nations. Vietnam’s travel restrictions — supported by other measures, including enforced quarantining and contact tracing — help explain the country’s apparent mastery over the virus. And while the political leverage of a single-party government might have helped Vietnam respond faster and more unilaterally than others, “I don’t think this is simply about totalitarianism versus Western democracies,” said Kelley Lee, a Simon Fraser University global health professor who has been studying the impact of travel restrictions.

That’s why Vietnam is now among a few countries upending the global health community’s “almost religious belief that travel restrictions are bad,” said Lawrence Gostin, a Georgetown University global health law professor who helped write the international law governing how countries should deal with outbreaks.

“I have now realized,” Gostin added, “that our belief about travel restrictions was just that — a belief. It was evidence-free.”

Covid-19 changed the thinking about travel restrictions in a pandemic

At a time when people still thought diseases originated with imbalances in the “four humors” and doctors routinely used treatments like bloodletting, governments tried to manage travel to prevent outbreaks. In 1377, quarantine measures were introduced in Dubrovnik, on Croatia’s Dalmatian Coast, to keep out sailors potentially carrying the bubonic plague.

The law stipulated that anyone from “plague-infested areas shall not enter [Dubrovnik] or its district unless they spend a month on the islet of Mrkan … for the purpose of disinfection.” For land travelers, the disinfection period lasted even longer — 40 days.

But in the age of mass travel and globalization, it seemed virtually impossible — counterproductive, even — for cities or countries to isolate themselves. The mantra in global health became “diseases know no borders.” Just before the pandemic, 2019 was a record year for tourist arrivals. The travel and tourism sector had generated a tenth, or US $8.9 trillion, of global GDP. “It [was like] the cat’s out of the bag,” Gostin said.

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Many of the measures countries tried in recent years, after the first SARS virus emerged in 2002 — including banning flights or visas for particular cities or countries, and screening for disease at airports — didn’t seem to deliver much protection.

Research on SARS, Ebola, and the seasonal flu found these targeted restrictions merely delayed infections and carried a slew of social and economic costs. They unfairly punished the economies of places that were unlucky enough to be plagued by disease, interfered with the global flows of people and goods, drove infections underground, and made it hard for aid workers and supplies to reach those that urgently needed them.

I knew these costs intimately. I grew up in Toronto, where a rare travel advisory imposed on the city by the World Health Organization in the wake of the first SARS outbreak cratered tourism to the entire province — so much so that the Rolling Stones eventually intervened with a charity concert (dubbed “SARSStock”). The measures also failed to avert outbreaks. According to a Canadian government report, putting arriving passengers through health assessments and thermal scanners didn’t root out a single case.

During the 2014-2016 West Africa Ebola epidemic and early in the Covid-19 pandemic, I co-wrote popular stories detailing this evidence and arguing against the use of such restrictions. And I wasn’t alone.

Bill Gates pointed out that then-President Donald Trump’s approach to Covid-19 travel bans probably made the US epidemic worse. The WHO’s International Health Regulations, an international law governing 196 countries’ responses to outbreaks, says countries should “avoid unnecessary interference with international traffic and trade” and follow the WHO’s expert advice. With every global health emergency declared after SARS, the WHO has not recommended travel restrictions.

At the same time, speaking out against travel bans had become synonymous with opposing nationalism and wall-building, said Lee. “There were these progressive, human rights values that were upheld by not using travel measures.”

But it’s now clear that the well-meaning advice and previous research findings didn’t match up with the situation the world was facing in early 2020. The new virus was different — more contagious and harder to stop. SARS-CoV-2 can be transmitted prior to the onset of symptoms, if they ever occur — while with SARS and Ebola, for example, people are only contagious when they are very ill or symptomatic.

The new coronavirus contagion inspired drastic measures. After China locked down Wuhan in January 2020, a move many called “draconian,” countries around the world scrambled and experimented with their own travel restrictions. Only a few, though, did something that “seemed unfathomable” prior to the pandemic, said University of Hong Kong public health professor Karen Grépin: They completely closed their borders. It was an approach experts had no evidence for. “No one [had] modeled out a scenario in which borders would be shut,” she said, and stay shut.

Yet that’s essentially what happened in Vietnam — and in a few states or regions, mostly islands including Taiwan and New Zealand, that have virtually eliminated the virus.

Vietnam started building a “wall” to the world in January

Early last year, when the US and European countries still focused on keeping out travelers from places with known Covid-19 cases, Vietnam closed its borders to the world.

It was the culmination of months of escalating travel restrictions. On January 3, the same day China reported a mysterious cluster of viral pneumonia cases to the WHO, Vietnam’s Ministry of Health issued a directive to increase disease control measures on the border with China. By the end of January, Vietnam’s then-Prime Minister Nguyen Xuan Phuc banned all flights to and from Wuhan and other areas where the virus was spreading in China and shut off every transport link between the two countries, making it the first place in Southeast Asia to close out Chinese travelers.

By mid-March, Vietnam suspended visas for all foreigners and then stopped all commercial flights. Only diplomats, citizens, and other officials could get in or out on repatriation flights, and they needed authorization from the government to enter.

Limited air travel has now resumed with other low-risk neighbors — such as South Korea, Taiwan, and Japan — but only for Vietnamese people and foreign businesspeople and experts. And while Vietnamese nationals can cross land borders from Laos or Cambodia, everybody who does get into the country — by air, land, or sea — has to submit to PCR tests and wait out a mandatory 14- to 21-day quarantine period under state supervision in a military-run facility or designated hotel.

So where Western countries introduced travel restrictions late, targeted their measures at countries with confirmed Covid-19 cases (or variants now), made quarantine optional or didn’t enforce it, and allowed loopholes (like excluding certain groups from travel restrictions, or letting people arriving over land avoid quarantine), Vietnam walled itself in. While Western countries continue to roll measures back whenever case counts come down, Vietnam has kept its wall up — even during periods when the country recorded zero new coronavirus cases.

“This is the lesson about border measures that’s changed,” Grépin said. “The value of border restrictions goes up the fewer cases you have.”

The restrictions also appear to work best if they’re implemented when they most seem like overkill, said London School of Hygiene and Tropical Medicine epidemiologist Mark Jit. That is, before (or after) community transmission takes place, he added.

“The natural thing is to think, ‘When we have a big problem, there are many Covid cases, that’s the point when we need to start doing a lot of things.’ But for travel restrictions — these are the solution to stop the problem from happening in the first place,” Jit explained. “It seems obvious in retrospect, but it’s very paradoxical.”

Vietnam saw China’s epidemic as a threat right away

So why did Vietnam take this early and comprehensive approach when so many other countries didn’t? The short answer: The country’s fraught relationship and porous border with China — which put it at higher risk for outbreaks — may have been its savior.

“[The] two countries taking the quickest action are Taiwan and Vietnam — they shared the same reasons: geographical proximity to and distrust in China,” explained Nguyen Xuan Thanh, a member of the Prime Minister’s Economic Advisory Group, which is composed of experts who counsel the government on economic development strategy and policy. (Vietnam may have had information that other countries didn’t early on: A cybersecurity firm, FireEye, has said that since at least January, Vietnamese hackers spied on the Chinese government to collect intelligence about Covid-19 — reports the government has denied.)

Whatever the reason, officials in Vietnam didn’t entertain the possibility that the coronavirus was just like the seasonal flu, nor did they consider herd immunity. When China locked down Wuhan last January and bought other countries time to react, Vietnam was one of only a handful of countries that used that time wisely.

Hoang An/AFP via Getty Images

“Outside of the Asia-Pacific region, most of the world did very little to prepare for the real possibility that this virus was about to spread globally,” Grépin said. In January, the Vietnamese government set up a national task force specialized in handling Covid-19, headed by the deputy prime minister, and defined a “double goal” — combating the virus and growing the economy.

The country’s officials and Communist Party made battling Covid-19 a patriotic act. “Fighting this epidemic is like fighting the enemy,” the prime minister said in a government meeting last January.

They transmitted health messages to the public using creative tactics, like texts to mobile phones or a viral pop song about hand-washing. They ramped up testing (starting in January 2020) and shortly thereafter began checking even asymptomatic people for the virus. By the end of last year, Vietnam was processing 1,000 tests per Covid-19 case, compared to 12.8 in the US or 21.7 in the UK.

Contact tracing became so widespread that the population now speaks the language of epidemiologists: It’s not unusual to hear Vietnamese people refer to the “F1” through “F5” system — how contact tracers denote a person’s proximity to an “F0,” or index case. (And, yes, where Western governments largely abandoned contact tracing or didn’t even seriously attempt it, Vietnam continues to ferret out potential cases by testing all F1s — a patient zero’s immediate contacts — and quarantining them in a state facility, while also asking F2s to quarantine at home.)

Linh Pham/Getty Images

When a single person tests positive, it can trigger a targeted lockdown, “isolating a large area when the fire is big, isolating a small area when the fire is small,” Mai Tien Dung, the chair of the Office of the Government, said.

In practice, this meant that last February, just as Lunar New Year travel and Vietnam’s third wave was picking up, a Hanoi apartment block, where more than 1,000 people live, closed down one evening after a woman tested positive for the virus. The entrances were barricaded and guarded by police as hundreds of residents spilled out, masked and social distancing, waiting for a free Covid-19 test.

Only those who tested negative were allowed to leave, and results took at least six hours to come in — a fact that frustrated those who weren’t prepared to spend the night, like gym staff members. By the next morning, everyone who had been tested got a negative result, and the barricades were removed — but everybody living on the two floors around the index patient was asked to quarantine for two weeks.

Vietnam also bet that the early overreaction, including closing down international borders, might save the domestic economy and prevent the health system from becoming overwhelmed, Thanh said. Just before SARS-CoV-2 started spreading in China, Vietnam ranked 73 out of 195 countries on epidemic response and mitigation, according to the Global Health Security Index from the Johns Hopkins Bloomberg School of Public Health. (The US, meanwhile, ranked No. 2 after the UK; the top 10 included the Netherlands and Brazil.)

Vietnam had another vulnerability to contend with. “The reality [is] that Vietnam does not have enough budget to sacrifice the economy and support businesses and individuals who had to cease operation,” Thanh said.

More than a year later, Vietnam’s success with keeping case counts, hospitalizations, and deaths low laid bare the arrogance and faulty assumptions that went into determining which countries would win or lose in their battles with the virus. With the exception of short-lived, targeted lockdowns, life in Vietnam today largely resembles the Before Times in a way many Westerners can only envy. People go to bars, share drinks with friends, and enjoy live music. Restaurants and cafes are open. Children attend school and see their grandparents in person.

The population never experienced the disorientation, economic pain, and mental health toll of rolling national lockdowns. Hospitals never buckled under the strain of masses of coronavirus patients. Kids didn’t miss a year of school. (There was a brief nationwide social distancing order last April when all schools were shut for three weeks.)

Vietnam is also one of a handful of countries whose economies grew in 2020 — the same year the country introduced three trade deals and saw per capita income rise. “At the beginning of the crisis, if you asked an economist what would happen here, most of us were pessimistic because of the [cutting off of] connections to the rest of the world,” said Jacques Morisset, the World Bank’s lead economist for Vietnam.

But because the virus was quickly contained internally, the domestic economy rebounded, just as Thanh and his colleagues had hoped. Manufacturing continued, and exports grew by 6.5 percent — not far off from the usual export turnover increase of 8 percent, according to Thanh.

That growth more than made up for losses in the shrinking tourism and transport sectors. The successes also helped foster public support for the anti-virus measures. Whenever the tourism or travel industries lobbied for open borders, the economic pressure didn’t crack the borders open. According to a survey released in December by the UN Development Program and the Mekong Development Research Institute, 89 percent of Vietnamese respondents said they supported the government’s approach — higher than the global average of 67 percent.

“Politicians make decisions based on the pressure from the society and inner political system,” Thanh said. “Vietnam had no such pressure. Vietnamese people supported the government to continue having strict measures.”

Vietnam’s state security apparatus bolstered its public health response

In a one-party system like Vietnam’s, there are few avenues to voice opposition. This political context has arguably strengthened certain anti-virus measures, like the country’s extensive contact tracing program. The Communist Party has for decades employed “surveillance, physical monitoring, and censorship to manage the population,” Foreign Policy reported in May last year. These “tools of Communist Party control … have now been repurposed in the service of health protection.”

Local officials and busybody neighbors also exert social pressure on others to confirm, said Carl Thayer, a Southeast Asia specialist and emeritus professor at the University of New South Wales. “Vietnam has block wardens, village wardens, household registration, and inquisitive locals that intrude on people’s lives. They have a society where people report people.”

The government can and does share details with the public about positive cases (including the age, gender, and neighborhood where the person lives, as well as a flight number for travelers), sometimes leaking additional information for use as cautionary tales.

Perhaps the most infamous example: Vietnam’s case number 17, a socialite who traveled to Italy without disclosing it at the border and faced severe public shaming. Her Covid-19 experience was the subject of government press conferences, and social media users tracked her down. Her story scared people who didn’t want to be responsible for others’ infections, said Hanoi-based American health economist Sarah Bales. “Everybody knows her,” she said. “She was notorious, and people hated her.”

This heavy-handedness would not be tolerated in many Western countries, where concerns about personal freedom and privacy have often trumped public health throughout the pandemic, Thayer said. The Foreign Policy authors also pointed out that the country’s human rights violations have repeatedly been overlooked in examinations of Vietnam’s Covid-19 response: “While the international community has criticized Vietnam’s security apparatus in the past for violating its citizens’ rights, the country has received near-unanimous praise for its successful handling of the current pandemic. But the tools used are the same.”

Yet to reduce Vietnam’s Covid-19 success to its system of authoritarian governance is a mistake, Lee said, pointing out that democracies, like South Korea, Taiwan, and New Zealand, have employed similar tactics as Vietnam. And analysts have repeatedly struggled to link a country’s political system to its Covid-19 success.

Vietnam’s is “a very scientific approach and has merit on its own no matter which regime chooses to apply these types of measures,” said Bales, who has lived and worked in Vietnam since 1992. “They did extensive contact tracing. … They did massive testing. They closed down the provinces so if there was transmission, it would stay local. Most people are living a normal life, and the few people who have been exposed or infected have to bear the brunt of quarantine, testing, and isolation.”

Watching the pandemic unfold in the US and Europe, Bales was among several Vietnam-based Westerners who told Vox they believe the privacy and personal liberty costs during the pandemic were worth the benefits of living a relatively free life.

“You don’t have to worry and be afraid like you do in the West — where every time you go out, it must be stressful [wondering] about if you’re exposed and if you’re exposed, will you have long Covid or die,” Bales said. “On a day-to-day basis, I don’t worry.”

When Vietnam’s wall comes down

One morning in early March, a taxicab pulled up to the international terminal at Hanoi’s Noi Bai airport. The last time the driver took someone there was half a year ago, he said, when a Vietnamese customer wanted to fly to Taiwan for work. Today, though, a repatriation flight had just landed — one of 16 arriving in Vietnam so far this year.

Inside, the airport is a skeleton of its former self. There are no crowds waiting to greet friends and family. Cafes and restaurants are closed, and the terminal halls are quiet and dark. A group of the newly arrived passengers waiting at the luggage conveyer belt look distinctly like they’ve come from a biosafety hazard lab: wearing blue full-body protection suits and masks, provided by Vietnam Airlines staff when they boarded their flight in Paris.

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The only loud noise echoing across the terminal is a voice broadcasting instructions for what the passengers need to do next: Everybody will be transported to state-supervised quarantine facilities. One by one, their names and year of birth are called out before they walk to buses to be ferried off. When they arrive, they’ll be tested for Covid-19 — and, if positive, forwarded directly to the hospital for isolation and treatment.

“We will try our best to organize so that families, parents, and children can stay together,” the voice on the speaker says, “but with friends, we may not be able to do so. We are sorry for that.”

This scene feels unimaginable in Western cities like New York or Paris — but so did ubiquitous mask-wearing and lockdowns over a year ago. With travel set to boom as the pandemic eases, and the next outbreaks on the horizon, I wondered what the rest of the world should take away from Vietnam.

Lee — and the other global health researchers I spoke to — advised caution. This pandemic showed travel restrictions can be helpful, but we should not make the same mistake we did in the past and assume what worked for the coronavirus will work for other health threats. “We don’t want countries to automatically control borders whenever a cluster of atypical pneumonia occurs,” Lee said. “Not all outbreaks require borders to be closed.”

Shutting borders comes with costs — all the people who lost travel and tourism jobs in Vietnam over the past year, or those who have been stranded far from home. Because of the very limited access to repatriation flights, thousands are waiting for their applications to get approved, and a black market for repatriation flight access sprang up. The wealthy agree to pay as much as $10,000 US for seats, while some have been scammed.

“Even if we conclude that travel restrictions and trade restrictions and migration restrictions — under certain targeted circumstances — can be an effective part of the package,” Gostin said, “we still have to take into account the fact that by implementing [them], you’re causing harms in other regards.”

Grépin also warned that the border closures countries like Vietnam put in place were “very extreme,” and pointed out that less intensive measures might prevent cases and carry fewer costs. Places like South Korea, Singapore, and Hong Kong, for example, have shown that “if you quarantine incoming travelers you can limit public health risk without border closure,” she said. But she also noted the approach isn’t foolproof. Hong Kong, for example, is currently struggling with the virus because of its travel links with India: A single April 4 flight from New Delhi has led to more than 50 Covid-19 cases.

This raises another challenge: Travel restrictions are difficult to calibrate correcrtly, said Steven Hoffman, a global health professor and the director of York University’s Global Strategy Lab. “If we are going to make use of [total border closures,] we need to [acknowledge] the fact that it might be implemented for events that don’t go pandemic,” he said. “And there’s something like 200 events every year that could go pandemic.”

For now, as Vietnam weighs the benefits of Covid-19 vaccine passports and how to resume international travel, one thing is certain: The walls the country has built up will come down. People will hop on trains, planes, and buses, bringing their germs with them. The world will get smaller again, and proximity will be “more determined on the basis of the quantity of travel connections than kilometers,” Hoffman added.

Vietnam’s early, quick response to Covid-19 was inspired, in part, by the country’s shared border with China. But what other countries need to learn is that, in a globalized world, they share borders with China, too.