The Impact of Air Travel Restrictions on the Spread and Severity of the First Wave of COVID-19

By Lydia Smith

Lydia Smith is a 4th year Foreign Affairs major and a French and Russian minor. She is also a member of the UVA Women’s Rugby team and Shakespeare on the Lawn. Her article is taken from the introduction of her Distinguished Majors Program thesis, where she is writing on the impact of air travel regulations on the first wave of COVID-19.

I am very pleased to see that Lydia Smith’s paper, “The Impact of Air Travel Restrictions on the Spread and Severity of the First Wave of Covid-19” will be published in the Virginia Journal of International Affairs Lydia’s article is part of the research she is conducting in the Distinguished Major Program in the Department of Politics. On the one hand, Lydia seeks to explain how international air traffic might have contributed to the worldwide spread of Covid, and on the other hand how stopping that traffic is fraught with difficulties. It is not only that stopping air travel has negative political and economic consequences, but the timing of the stoppage usually arrives after the pandemic has already started. In fact, it is only in the aftermath of Covid’s spread, that most governments banned international air travels. The bans were thus imposed too late to prevent the contagion. As Lydia put it: “although they seem to be effective if put in place immediately, they do not appear to be significantly effective over the long term during a global pandemic.”

Lydia derives this conclusion from several case studies that vary in terms of the volume of air traffic. She identified New York, Singapore, and

Sweden, as territories with high levels of air traffic that enacted, however, quite different policies on international travels. She also studied Libya and Venezuela as countries that have relatively low levels of air traffic, which imposed strict public policy measures which they ultimately had difficulty enforcing.

Lydia is not quite finished with her research, and she is still drafting her thesis. As the chair of the DMP, I have been privileged not only to have her as one of the eleven students enrolled in a yearlong seminar, but I have also been her thesis advisor. We have had several long conversations about her research, and she will complete her thesis in late April and present it at a DMP meeting in presence of the other DMP students and their advisers. I expect Lydia to produce a first-class thesis on a topic of vital interest.

Robert Fatton Department of Politics

University of Virginia

Abstract

This article looks at restrictions on travel implemented in an effort to mitigate the effects of the first wave of the COVID-19 pandemic. The link between air travel and the spread of infectious diseases has been welldocumented before the onset of COVID-19; however, in the context of the 21st century, travel restrictions had to have been imposed at the very moment the disease began in order to prevent the global spread of a pandemic. Undoubtedly, travel restrictions would have slowed the spread of COVID-19 significantly and would have had clear benefits had they been implemented before the virus spread to every country; however, though every country had put some sort of air travel restriction in place before the first few months of the pandemic were out, most of these restrictions came too late to make a significant difference. This article examines the examples of New York State, Sweden, Singapore, Libya, and Venezuela and ultimately argues that the travel restrictions imposed by world governments were ineffective at stopping the spread of the pandemic.

Where people go, disease follows. We have understood that for centuries, and the use of travel bans, quarantines, and stay-at-home orders to try to prevent the spread of infectious diseases can be traced back to the Black Plague and earlier. The most effective way to overcome an illness, it would seem, is to stop it from reaching you in the first place. While in decades past human travel was largely limited by how far it took to get somewhere by land or by sea, modern-day commercial air travel allows us to fly halfway around the world in under twenty-four hours; hence, a new disease can spread just as rapidly.

With this in mind, it is necessary to impose travel restrictions almost immediately in order to prevent a pandemic from going global. In the case of a virus like COVID-19, which can spread before symptoms even begin, those restrictions need to be put in place before the threat is even noticeable. Undoubtedly, successful travel restrictions would have slowed the spread of COVID-19 significantly and would have had clear benefits had they been implemented before the virus spread to every country; in practice, although every country had put some sort of air travel restriction in place during the first few months of the pandemic, in the vast majority of cases, these restrictions came too late to make a significant difference. By the time they were imposed, the virus was already virtually everywhere and had in many places become self-sustaining, meaning that travel restrictions did very little to stop the epidemic from spreading.

Of course, COVID-19 was not the first significant epidemic which spread largely via air travel. In 2002, the SARS epidemic spread to twentynine countries and caused several local epidemics (Findlater and Bogoch 2018, 775). Ultimately, public health measures were successful in containing the virus, and this case was instrumental in demonstrating the need for international cooperation in order to successfully combat the spread of infectious disease, especially during a time when it can spread so rapidly. After the SARS epidemic made it clear that the likelihood of a pandemic spreading due to air travel was high, more research explored the links between air travel, passenger volume, and disease transmission. One particularly applicable study conducted by Liang Mao et al. noted that the World Health Organization could potentially use its data to track high-risk routes and predict where infectious diseases could spread (Mao et al. 2015, 59). Such preemptive analysis of airport patterns could be vital in the early stages of a pandemic, when contact-tracing and understanding where a disease is spreading is critical for effectively stopping it.

In mid-December of 2019, hospitals in Wuhan (in the province of Hubei, China) began to receive patients with a mysterious flu-like illness. By late December, Chinese doctors began to warn people about the disease through social media despite backlash from the Chinese government. On December 31, the Huanan Seafood Wholesale Market, which was a possible starting point for many early cases of the virus, was closed by authorities, and on January 3, 2020, China officially reported the outbreak to the WHO. Almost as soon as knowledge of the virus became public, speculation began that there was a significant risk of importation of the virus via air travel. The first official case outside of China was identified in Thailand on January 13, but whether other international cases might have gone unreported in those early days is unknown. The risk of the virus spreading to countries with high levels of travel contact with China was significant, and it was estimated that countries with multiple central travel hubs (for example, Germany, which has several major airports) would be more vulnerable to early spread than countries with less air travel or only one major travel hub (Pullano et al., 2020).

The celebration of Lunar New Year in mid-January 2020 led millions of people to travel to and from Wuhan, most likely exacerbating the spread of the virus. At 2 a.m. on January 23, officials announced a lockdown via a notification sent to local smartphones. Airports, train stations, and buses were shut down at 10 a.m. local time, initiating a quarantine that would last until April 8, 2020 (Timeline: China's COVID-19 outbreak and lockdown of Wuhan, 2022); however, because the doubling time of COVID-19 was four to five days, it is estimated that the early Wuhan travel ban delayed the spread of COVID-19 within mainland China by less than a week. By late January, COVID-19 had spread to several other major cities within China, and because up to 75 percent of very early cases also went undetected, it is possible that COVID-19 spread to several other cities domestically and internationally without anyone realizing (Chinazzi et al., 2020).

One study published on January 30, 2020, estimated that it was extremely likely that COVID-19 would eventually spread to every country in Europe. This study took into account the many cases that went undetected and contributed to the international spread without being officially counted. Despite the travel ban to Hubei province, COVID-19 had already spread to other provinces and cities and was thus able to spread internationally (Pullano et al., 2020). It is important to read early studies like this one in order to understand the perspective of global health officials and governments at the time. Thanks to SARS and other epidemics, the global health community was well aware of the risk of disease importation from the earliest days of the COVID-19 pandemic, and as early as January, many experts were advocating for widespread travel bans in order to stop the spread of COVID-19 to other countries. Unfortunately, most governments did not take quick action.

In early February, fifty-nine airline companies limited or suspended flights to mainland China, and many governments imposed travel restrictions; however, because the pandemic had already spread to other countries and was spreading domestically at an exponential rate, those travel restriction measures did not stop COVID-19 from spreading to virtually every country in the world. One study published in March 2020 by Matteo Chinazzi et al, found that the restrictions imposed by the United States were ineffective unless they were combined with strict domestic containment measures. The study used a metapopulation disease transmission model which divided the world into subpopulations grouped around airports. The researchers took data from previous studies of the flow of air traffic, as well as data from the International Air Transport Association, and they factored in age and health when considering how mobile different populations were likely to be. This research. found that even a 90 percent decrease in travel to and from China would only delay the spread of COVID-19 for less than two weeks (Chinazzi 2020). In the long run, domestic containment measures and public health education would be much more effective than travel restrictions in stopping the spread. By summer 2020, imported cases made up less than 10 percent of cases and travel restrictions had a very small impact on the overall caseload in most countries. Very stringent travel restrictions only had a significant impact where there were already very low caseloads of COVID-19 coupled with very large numbers of arrivals from other countries; however, because there was a strong correlation between international travel and high levels of COVID-19, not many countries fit that description, and stringent travel restrictions were not generally very impactful (Russell et al. 2020, 12) .

Aside from their conditional practicality, there are other reasons why travel restrictions should not be and are not always immediately imposed as the first line of defense. According to the 2005 International Health Regulations, which were heavily revised after the SARS epidemic, travel restrictions “shall not be more restrictive of international traffic and not more invasive or intrusive to persons than reasonably available alternatives that would achieve the appropriate level of health protections” (Revision of the International Health Regulations, 2005). There are humanitarian, economic, and legal reasons to ensure that travel restrictions are only implemented when the benefits outweigh the costs.

Among the other obstacles to travel restrictions’ efficacy at containing the spread of disease is the complexity of implementation. In order to screen incoming travelers, airports face logistical problems arising from the inaccuracy of self-reported symptoms, the need to temperaturescreen travelers, and the possibility of asymptomatic travelers potentially spreading the virus. Additionally, most governments did not implement travel restrictions in time to stop COVID-19 from entering their countries in 2020 because airlines have economic incentives to maintain high connectivity. While many airlines did suspend travel independently, government regulation earlier in the process could have led these travel bans to be more effective. Internationally, public support for travel restrictions is mixed. In 2021, Steffen Kallbekken et al. conducted a study suggesting that public support for air travel restrictions due to COVID-19 was initially high as the public perceived the pandemic to be an imminent and severe threat; but support for travel restrictions lessened as time went on because the public began to expect extended negative consequences and because the severity of the pandemic no longer sat at the front of the public’s mind. Even when governments managed to put bans into place, different countries enacted different policies, causing inconsistency and complications. To understand how these different policies worked, it is useful to look at several representative case studies: New York, Singapore, Sweden, Libya, and Venezuela. The cases of New York, Singapore, and Sweden are revealing because they are all places with high levels of air traffic that enacted very different policies with regards to international travel and domestic measures. Libya and Venezuela, on the other hand, are useful case studies because both countries have relatively low levels of air traffic, and although they both implemented strict quarantine measures, those measures were difficult to enforce.

After the first official case of COVID-19 was confirmed on March 1, 2020, New York State closed schools, houses of worship, and large gathering facilities and declared a state of emergency on March 7, 2020, a week before the United States government declared a national emergency. On March 12, a federal travel ban was implemented that prevented European Union nationals from entering the United States, and borders were closed to other countries, including Canada, by the 18th. New York, however, never banned travel between states, meaning that it was still possible for people to travel and spread the virus within the United States. As COVID-19 was already spreading in New York at an exponential rate, and federal travel restrictions did not prevent people from moving from one state to another, the restrictions had very little impact on slowing the spread of COVID-19 in New York and in the United States (Tiwari et al, 2021).

In Sweden, the first case of COVID-19 was reported on January 31, 2020. Restrictions in Sweden were very relaxed domestically, though public gatherings of more than 500 people were prohibited on March 11, and citizens were advised against all unnecessary travel on March 13; however, the decision to allow schools to close was left up to the individual schools, and the Swedish government deemed social distancing and quarantine voluntary. A study done by Bo Yan et al. noted that Sweden has a very individualistic culture and a decentralized regime, with historical preference for individualism over collectivism. This may help to explain Sweden’s “nudge” strategy of pandemic response: The government designed its response to change behaviors without prohibiting options or imposing upon individuals’ freedom of choice.

Sweden’s relatively relaxed approach was the subject of much criticism, as it differed from the strategies of Sweden’s neighbors. Sweden could have enacted much stricter lockdown measures, and it received criticism for leaving things relatively open (Claeson and Hanson 2021). Notably, when Prime Minister Stefan Lofven gave his first televised address to the nation regarding COVID-19 on March 22, he made no mention of concrete policy changes; instead, he asked Swedes simply to “play their part” (Prime Minister’s address to the nation, 22 March 2020, 2022). Sweden was the only country in Europe that did not impose a general lockdown. During the first wave of COVID-19, Sweden fared worse than its Scandinavian neighbors, though perhaps not to the degree that one would have expected. Sweden’s many pre-existing advantages, such as a relatively healthy population, high GDP per capita, and less international travel than other major European cities may have contributed to Sweden’s unusually low COVID-19 case rate, despite looser restrictions.

In contrast to Sweden, Singapore responded to COVID-19 by imposing very strict public policy measures. The government created a COVID-19 task force before the first official reported case and enacted an intense lockdown on April 10 (albeit this was later than most other nations). Today, Singapore has one of the lowest case fatality rates in the world thanks to mass testing, contact-tracing, quarantining, and a rigorously-structured medical plan. In this case, it seems that Singapore’s domestic measures were incredibly effective at slowing the spread of the virus, despite the fact that Singapore did not enact a travel ban until nearly a month after most other countries.

Saleem Ahmed et al. give a first-hand account of what it was like to be a doctor in Singapore during the early stages of the pandemic, stressing how quickly Singapore implemented measures domestically to curb the spread. These measures included emergency hospital response plans, the prioritization of COVID-19 patients when possible, and streamlined clinic and hospital services (Ahmed 2020, 1075-1076). John E. L. Wong et al. also describes Singapore’s early countermeasures, including their extensive travel restrictions and contact-tracing policies. Wong et al. argue that Singapore learned from its experience with SARS and was therefore relatively better prepared for COVID-19 than most other countries (2020).

In contrast, Libya was relatively ill-equipped to respond to the pandemic. Libya’s first confirmed case was reported in Tripoli on March 24, 2020. The Libyan healthcare system was not prepared to handle a pandemic, and continuous armed conflict prevented the government from enforcing its quarantine and isolation orders. The conflict also hurt healthcare infrastructure and made it impossible to know for sure how badly the pandemic has affected certain areas; however, Libya has had fewer COVID-19 cases than many other countries, possibly due to Libya’s low rate of international air travel or alternatively, the high rate of Bacillus-Calmette-

Guerin vaccinations. In sum, 98 percent of Libyans have had this vaccine, which may have built immunity to respiratory viruses like COVID-19, prior to the COVID-19 pandemic (Gasibat, Raba, and Abobaker 2020). This validates the correlation between air travel and rate of infection, despite domestic policy drawbacks.

Similarly, Venezuela has experienced much fewer COVID-19 cases than its neighbors. The first confirmed case was reported on March 13, 2020, and the government announced a stay-at-home order two days later and a lockdown two days after that. It is possible that low levels of international travel may have delayed the initial spread of COVID-19 in Venezuela because although Venezuela did employ domestic containment efforts, it was very difficult to enforce a quarantine order because so much of the population needed to go outside of their homes daily to work and to obtain basic necessities like food and water (Cooper 2020, 241-5).

Although the data for Libya and Venezuela especially is difficult to draw causation from, there is a strong correlation between high levels of international traffic and high levels of COVID-19, at least during the beginning of the pandemic. However, there is less proof that international travel bans were effective, especially when compared to domestic efforts to slow the spread. Internationally, support for travel restrictions is mixed. Steffen Kallbekken et al. conducted a study that showed that, at least initially, public support for air travel restrictions due to COVID-19 was high, as there is a perceived threat and imminence of the problem. Kallbekken et al. explain that this is because people expect that these restrictions will go away soon, but that the support for travel restrictions lessens when there are perceived extended negative consequences (2021).

However, some critics argue that travel restrictions violate international law, and that although they might be useful in containing pandemics, their costs are more than their benefits. They argue that travel restrictions do more harm than good, particularly in today’s global economy, and that although they slow the pandemic, they did not effectively stop it. Travel restrictions can be very damaging to a nation’s economy, and the brunt of travel restrictions’ negative effects is forced onto countries who have large tourism sectors. Additionally, there is some research suggesting that travel bans can lead to increased levels of racism and xenophobia, and can discourage globalization and international cooperation (Meier 2020).

Clearly, travel restrictions are a complex issue, and there is no clear solution, especially during times like early 2020, when there were few places to look for precedent. In conclusion, restrictions are effective if governments impose them immediately, but they are not otherwise significantly effective over the long term of a global pandemic.

Despite travel restrictions’ contested effectiveness, this pandemic still might change air travel forever. The Lancet journal published an article that suggested that the impact of COVID-19 on air travel could be comparable to that of 9/11, when TSA and other security measures were widely implemented. It is difficult to predict what will happen, especially since the pandemic is ongoing, but it is not hard to imagine that measures such as wearing masks on planes might become commonplace for many years to come.

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