The boarder between the United States and Mexico. Share on Pinterest
A new study questions the effectiveness of international border closures during the COVID-19 pandemic. Sherry Smith/Getty Images
  • Despite the World Health Organization (WHO) advising against border closures, nearly every country imposed border restrictions during the COVID-19 pandemic.
  • New research finds no evidence in favor of international border closures to stop the spread of SARS-CoV-2.
  • Experts say efforts should focus on what we know does work, including mask-wearing, social distancing, and vaccine uptake.

During 2020 to 2021, nearly every country in the world imposed border restrictions to curb the spread of SARS-CoV-2, the virus that causes COVID-19, despite the practice being advised against by international health organizations.

Whether border closures are an effective means to contain a virus and protect a country’s citizens has been a source of debate throughout the pandemic.

New research published in Nature’s Scientific Reports aimed to answer that question. The study found no evidence in favor of international border closures.

Before 2020, the impacts of border closures on stopping the spread of infectious diseases were largely unknown.

Since the beginning of the COVID-19 epidemic, the World Health Organization (WHO) has advised against applying travel and trade restrictions to countries experiencing COVID-19 outbreaks.

“In general, evidence shows that restricting the movement of people and goods during public health emergencies is ineffective in most situations and may divert resources from other interventions,” the organization said in a statement in February 2020. “Furthermore, restrictions may interrupt needed aid and technical support, may disrupt businesses, and may have negative social and economic effects on the affected countries.”

Despite this guidance, more than 1,000 new international border closures were introduced in response to the pandemic between 2020 to 2021.

From the early days of the pandemic, Mary Shiraef, a PhD candidate in comparative politics and political theory at the University of Notre Dame, studied the effects of border closures.

“Personally, traveling is part of my identity, and professionally, my dissertation requires me to be in the field and to cross international borders on a fairly regular basis,” she told Healthline. “Like many, I was struck in March 2020, wondering how long the pandemic would last and whether the border closures and other measures being introduced would help curb the fallout from this awful disease.”

To help shed light on this issue, Shiraef launched the COVID Border Accountability Project, which collected and verified data for more than 1,000 international border closures.

“We used a matching technique, which allowed for better comparative analysis across countries with similar underlying factors,” Shiraef explained. “Specifically, we controlled for countries’ degrees of economic development, political regime type, demographics, and healthcare capacities. We used a hand-coded database of international border closures covering 185 countries organized by weekly time periods, allowing 11,975 country-week observations.”

The study yielded null results, meaning the researchers did not find any evidence in favor of international border closures to curb the spread of SARS-CoV-2.

The study did find an association between domestic lockdowns and a reduction in the spread.

Joseph Fauver, PhD, an assistant professor in the department of epidemiology at the University of Nebraska College of Public Health, said he is not surprised by the study’s results.

“It’s on par with what we know so far about how infectious diseases like COVID spread internationally,” he said.

“It can spread asymptomatically, pre-symptomatically, people can test negative on rapid antigen tests and then positive the next day and spread it,” he continued. “So purely from a virus standpoint, it would be a bad assumption that if it’s in one country, it’s not anywhere else.”

While there is limited research on the effectiveness of border closures to prevent infectious diseases, a research review published in the Journal of Emergency Management in early 2020 came to the same conclusion.

Researchers from the University of Washington analyzed six studies looking at four infectious diseases that emerged in recent years: the Ebola virus, SARS (severe acute respiratory syndrome), MERS (Middle East respiratory syndrome), and the Zika virus.

While some evidence suggested border closures may delay the arrival of an infectious disease in a country by a few days or weeks, there was very little evidence that a travel ban eliminates the risk of the disease crossing borders in the long term.

Shiraef noted that especially early on in the COVID-19 pandemic, border closures may have unintentionally contributed to the spread of SARS-CoV-2.

“Halting travel options suddenly may incentivize people to travel sooner than they had, and/or travel more, for longer periods of time and through inefficient routes, allowing more opportunities for spread of the virus,” she said.

Closing borders isn’t something that should be taken lightly, experts say, especially when considering the ripple economic, political, and social effects.

Travel bans may also thwart the sharing of important information, as many experts warned following the discovery of Omicron in South Africa and subsequent border closures.

“The scientists in Botswana in South Africa were the first group to identify the variant and put the world on notice,” Fauver said. “They made that data publicly available, and it was met with international travel bans, which, in a sense, creates an immediate incentive for people not to share data. That’s the last thing we want right now.”

Shiraef said she and her colleagues would continue to study the effects of border closures, including any political motivations behind them.

“We hope to understand whether anti-immigrant sentiment was a significant motivating factor in introducing bans on entry to specific groups of foreigners, especially those which defied logic in public health terms and those which lasted for long durations of time,” she said.

She also hopes her research will help inform policy amid the ongoing COVID-19 pandemic and future pandemics.

“In the future, I hope policymakers think twice before introducing border closures following an outbreak,” she said.

Rather, experts say efforts should focus on what we know works, including mask-wearing, social distancing, and vaccine uptake.