The emergence of Omicron, the latest COVID-19 variant of concern, has triggered a flurry of new travel restrictions around the globe. Amid fears of higher transmissibility, greater virulence, and reduced vaccine efficacy, governments worldwide are scrambling to slow the variant’s spread. Initial restrictions mostly targeted countries in southern Africa, where officials first raised the alarm about Omicron, but travel from other regions has been curtailed as public health agencies have identified more cases. Canada, for example, recently added Egypt, Malawi, and Nigeria to its initial list of seven restricted states. Hong Kong, for its part, has banned the entry of nonresidents from a growing slate of countries in Africa, Europe, and North America.
The result of these measures—imposed almost two years into the pandemic—is a renewed sense of international chaos. Each government has targeted different countries according to widely varying sets of criteria. Some have banned entry by foreign citizens traveling through certain countries but not nationals returning from those same countries. Specific testing and quarantine requirements for arrivals from targeted versus nontargeted countries have been set that vary across states. All this diversity points to a continued lack of consensus about how best to mitigate the public health risks of travel during the pandemic.
Despite the confusion, however, two years of experience battling the virus has produced a set of valuable—if poorly adopted—lessons for how to manage travel during the COVID-19 era. Although public health agencies such as the World Health Organization (WHO) initially advised against travel restrictions, evidence gathered during the pandemic has shown that these measures can help control or slow the spread of disease if used appropriately. Unlike the current patchwork of restrictions designed to target Omicron, travel measures can be effective if they are internationally coordinated, informed by scientific evidence, and politically transparent. Deployed correctly, border management can enable international travel to continue, albeit at lower levels, in ways that genuinely control and mitigate the risk of COVID-19.
ROAD TO NOWHERE
The continued confusion about travel restrictions is partly due to the ever-evolving nature of available evidence on COVID-19. Upon declaring the outbreak a public health emergency of international concern in January 2020, the WHO advised against travel restrictions based on evidence from previous disease outbreaks. In the past, such measures proved unnecessary for controlling the spread of disease, caused avoidable economic and social harms, and incentivized states to conceal public health information. COVID-19, however, was different. As a respiratory infection spread through the air and carried by asymptomatic people in as many as one-third of cases, the disease presented a different problem from past outbreaks.
Globalization also complicated the challenge. Over the past several decades, societies have become deeply interconnected, and accessible international travel has been an important enabler and beneficiary of this transformation. International tourism, for instance, peaked immediately before the pandemic hit. The combination of a novel pathogen in a uniquely interconnected world limited the usefulness of previous thinking on travel measures.
Designing effective COVID-19 travel policies isn’t a lost cause.
To its credit, the WHO has adapted in response to changing circumstances. Instead of dismissing restrictions entirely, the organization now recommends a “risk-based approach” to international travel. Countries should conduct “systematic and regular risk assessments,” it says, to inform their travel and border policies. Variables that might be considered in these assessments include local epidemiological data, travel volumes, and public health capacity.
These new technical guidelines are undoubtedly a useful departure from the WHO’s previous stance. But it will take time to reach a scientific consensus that can inform real-time decision-making during future outbreaks. If used correctly, however, a risk-based approach would help determine if travel restrictions are needed, which variables are associated with the greatest travel-related risk, and which measures should be applied when. Until then, as the rise of Omicron has shown, this gap is often filled by a recurring cycle of new variants of concern followed by international panic.
Despite the current lack of agreed-upon standards, designing effective travel policies isn’t a lost cause. Scientific research has begun to identify valuable lessons about border management during the pandemic that can be put to good use. The first is that timing matters. Evidence suggests that countries that moved quickly to restrict travel at the earliest stages of the pandemic, such as Australia, Taiwan, and Vietnam, successfully reduced the number of imported cases of SARS-CoV-2, the virus that causes COVID-19. These countries have also suffered lower levels of infection and deaths during the pandemic.
The second lesson, however, is that timing is only part of the story. Although evidence from these countries might suggest that governments should restrict travel from specific high-risk jurisdictions at the first sign of trouble, the reality is more complicated. Unless a state has maintained testing and quarantine requirements for all international arrivals throughout the pandemic, targeted action will come too late. The latest variant is likely already circulating within a country’s borders by the time authorities anywhere identify and report it. Omicron, for example, was reported to the WHO by South Africa on November 24, but scientists believe it emerged in early October. This timeline means that the variant was already spreading globally when researchers identified it, and its exact origins may not be southern African.
The third and final lesson is that the globalized nature of contemporary travel means that trying to contain a variant through targeted travel restrictions alone is ineffective. Travelers regularly transit through third countries and regions before arriving at their final destinations and may not be forthcoming about their full itineraries if threatened with entry restrictions. Travelers can also simply reroute their journeys to circumvent any limitations.
Terms such as “travel bans” and “border closures” are therefore misleading. They suggest that countries can somehow slam their borders closed, effectively shutting out public health risks. In practice, however, hermetically sealing a country off on short notice and for an extended period of time is nearly impossible. It is also rarely necessary if states deploy effective testing and quarantine measures.
LEAVING ON A JET PLANE?
With these lessons in mind, governments must reframe the problem. Their goal should be not to hastily ban arrivals from targeted countries but to effectively manage the public health risks associated with cross-border movement. A range of proven measures can help them accomplish this objective.
For one, governments can temporarily control who enters their countries and under what conditions. States can identify specific categories of individuals permitted to enter (limited by nationality, purpose, or other criteria), thereby reducing the volume of travelers to those deemed “essential.” This allows governments to subject all authorized individuals to an agreed-upon level of testing, quarantine, and other measures shown by emerging scientific evidence to enable strong disease surveillance and prevent onward transmission. Governments can implement these measures prior to travel, at points of entry, and after arrival. Restrictions or outright bans are therefore one tool among a broader array of options.
By using this more holistic approach, a small number of jurisdictions—including Hong Kong, Israel, New Zealand, South Korea, and Taiwan—have maintained relatively stringent border management regimes throughout the pandemic by testing and quarantining nearly all international arrivals. Few exemptions have been granted. Alongside monitoring for high-risk arrivals, these measures are the gold standard for COVID-19 travel policies. It is thus no coincidence that by applying this approach, Hong Kong and Israel were among the first governments outside South Africa to identify Omicron—with no onward community transmission because the individuals who tested positive for the variant were still in monitored hotel quarantine.
Hermetically sealing a country off on short notice is nearly impossible.
Crucially, these governments also integrated their border management regimes with domestic public health efforts. Although some countries weathered the early stages of the pandemic by quickly applying and then sustaining effective travel measures, the most successful ones also rapidly implemented local testing and contact-tracing programs, as well as physical distancing and mask-wearing guidelines. In other words, travel measures are not just about buying time but about using it wisely to implement public health protocols.
By contrast, other countries, such as the United Kingdom and the United States, have followed a different playbook. They implemented testing and quarantine requirements much later in the pandemic and allowed many exemptions. Under the United Kingdom’s so-called traffic light system, for instance, travelers from “green” and “yellow” countries—supposedly low risk—were subjected to limited or even no testing and quarantine requirements. Although the British government revised these ratings based on new information, data gaps and the virus’s global circulation made managing risk in this way a questionable proposition. Since mid-2021, moreover, many countries have lifted testing and quarantine requirements to encourage domestic economic recovery.
Still, it is overly simplistic to equate stringent travel restrictions with overall success in controlling COVID-19. Many factors explain varying health outcomes across different countries. Nevertheless, for this particular pandemic, it is clear that border management is one policy area that governments need to get right.
Although research is slowly producing a set of best practices for COVID-19 border management, these measures clearly come with high economic and political costs. These can be direct, through financial losses incurred by the travel and tourism sector, or indirect, by hindering the free movement of people. The risk-based approach advocated by the WHO recognizes this collateral damage but offers no obvious methodology for navigating the tradeoffs. These are not purely scientific considerations, after all, and each decision invariably involves complex political choices about who should travel and under what conditions.
At the same time, however, public health goals can and should be aligned with other policy objectives. Poorly executed travel measures, such as the current bans targeting individual states, can inflict unnecessary economic and social pain and allow new variants to spread worldwide. They also punish countries for being good global citizens and encourage governments to hide rather than share information—outcomes that harm everyone. Effective border management, by contrast, means enabling travel to continue, albeit at lower volumes, in controlled ways that mitigate risk. The alternative is chaotic and piecemeal measures that harm travelers, the travel industry, local economies, and public health.
Observers have often celebrated New Zealand for best maintaining this difficult balancing act. Wellington’s border management during COVID-19 has been consistent over time, applied equally to all incoming travelers, and aligned with the evolving science. And although critics rightly argue that some sectors have incurred substantial costs, the overall economy has benefited from avoiding the frequent lockdowns that bedevil countries seeking to keep their borders relatively open.
As a new round of travel restrictions and bans run their course, governments around the world will have another opportunity to learn from their mistakes. Regardless of the political and practical difficulties they face, leaders must understand that effective risk mitigation requires coordination. They must work together to harmonize standards for testing, quarantine, and vaccine certification, among other measures, and to build consensus around the WHO’s new risk-based approach. This will require revising the WHO’s International Health Regulations and potentially agreeing to additional multilateral legal frameworks. It will also require individual countries to invest more in border capacities if they wish to keep large numbers of people moving safely. If, however, they continue along their current path, no one will go anywhere fast.