WHO on Public health considerations while resuming international travel
Many countries have halted some or all international travel since the onset of the COVID-19 pandemic but now have plans to re-open travel. This document outlines key considerations for national health authorities when considering or implementing the gradual return to international travel operations.
The decision-making process should be multisectoral and ensure coordination of the measures implemented by national and international transport authorities and other relevant sectors and be aligned with the overall national strategies for adjusting public health and social measures.
The gradual lifting of travel measures (or temporary restrictions) should be based on a thorough risk assessment, taking into account country context, the local epidemiology and transmission patterns, the national health and social measures to control the outbreak, and the capacities of health systems in both departure and destination countries, including at points of entry. Any subsequent measure must be proportionate to public health risks and should be adjusted based on a risk assessment, conducted regularly and systematically as the COVID-19 situation evolves and communicated regularly to the public.
The objective of this document is to provide governments, health authorities of WHO Member States and relevant stakeholders with elements to consider in adjusting international travel measures to the changing epidemiological situation of the COVID-19 pandemic, national public health and health service capacity available in countries and evolving understanding of the virus. This document should be read in conjunction with other relevant WHO guidance, particularly WHO COVID-19 Strategy update 14 April 2020, Considerations for adjusting public health and social measures, the Scientific Brief on transmission of SARS-CoV-2, 09 July 2020 and the WHO Strategic Preparedness and Response Plan (SPRP) .
3. FACTORS TO BE CONSIDERED FOR RESUMING INTERNATIONAL TRAVEL
Each country should conduct a risk-benefit analysis and decide on its priorities.
WHO recommends that priority should be given to essential travel for emergencies, humanitarian actions (including emergency medical flights and medical evacuation), travel of essential personnel (including emergency responders and providers of public health technical support, critical personnel in transport sector such as seafarers and diplomatic officers), and repatriation. Cargo transport should also be prioritized for essential medical, food and energy supplies. Sick travellers and persons at risk including elderly travellers and people with chronic diseases or underlying health conditions, should delay or avoid travelling internationally to and from areas with community transmission.
There is no “zero risk” when considering the potential importation or exportation of cases in the context of international travel. Therefore, thorough and continuous risk assessment and management will help identify, reduce and mitigate those risks, while balancing the socio-economic consequences of travel measures (or temporary restrictions) against potential adverse public health consequences.
The decision process should include an analysis of the situation, taking into account the local context in countries of departure and destination. The following factors should be considered: local epidemiology and transmission patterns, the national public health and social measures for controlling the outbreaks in both departure and in destination countries; public health and health service capacity at national and subnational levels to manage suspect and confirmed cases among travellers, including at points of entry (ports, airports, ground crossings) to mitigate and manage the risk of importation or exportation of the disease; and the evolving knowledge about COVID-19 transmission and its clinical features.
3.1 Epidemiological situation and transmission patterns at origin and destination countries
Because the COVID-19 epidemiological situation will vary among countries, international travel, carries different levels of risk of exportation/importation of SARS-CoV-2 virus, depending on the passenger’s country of departure and country of arrival. The epidemiological situation of COVID-19 in each country is available through WHO Situation Reports, which follow the transmission scenarios defined in the Interim Guidance WHO Global surveillance for COVID-19 caused by human infection with COVID-19 virus, 20 March 2020. Four scenarios are considered:
- No cases: Countries/ territories/ areas with no reported cases
- Sporadic cases: Countries/territories/areas with one or more cases, imported or locally detected
- Clusters: Countries/territories/areas experiencing cases, clustered in time, geographic location and/or by common exposures
- Community transmission: Countries/area/territories experiencing larger outbreaks of local transmission defined through an assessment of factors including, but not limited to:
- Large numbers of cases not linkable to transmission chains
- Large numbers of cases from sentinel laboratory surveillance
- Multiple unrelated clusters in several areas of the country/territory/area.
The risk of importation of cases in the country of arrival depends on a number of factors including the epidemiological situation in the country of departure and the country of arrival:
- When the country of departure and the country of arrival share a similar intensity of SARS-CoV-2 virus transmission, there is no substantial risk of potential impact on the current epidemiological situation.
- When the country of departure is experiencing a more intense transmission of SARS-CoV-2 virus than the country of arrival, the risk of adversely affecting the epidemiological situation in the country of arrival is higher.
- When the country of departure is experiencing transmission of lower intensity, then the risk of adversely affecting the epidemiological situation in the country of arrival is lower.
The above risk assessment should also take into account new knowledge as it emerges. Sub-national variations may be considered in both countries.
Countries should continuously plan for and assess their surge capacities for testing, tracking, isolating and managing imported cases and quarantine of contacts.
3.2 Public health and intersectoral capacity
Assessing the risk that imported cases could pose to the national response to the pandemic depends both on public health and health services capacity and the capacity of other relevant sectors.
WHO Interim Guidance on “Considerations in adjusting public health and social measures in the context of COVID-19,” highlights six areas required to minimize the risk of increased transmission of COVID-19: control of transmission including contact tracing and isolation, sufficient public health workforce and health systems capacities, minimizing risks in high-vulnerability settings, workplace preventive measures, managed risks of importation or exportation from communities with high risks of transmission and full engagement of communities. WHO has developed detailed technical and operational annexes for most of these areas and provides a set of criteria to assess the need for adjusting public health and social measures at national level :
1) Is the epidemic controlled?
2) Is the public health surveillance system able to detect cases and contacts and identify any resurgence of cases, particularly among travellers?
3) Is the health system able to cope with a resurgence of COVID-19?
The WHO updated COVID-19 Strategy  has outlined objectives in relation to sectors beyond health, such as foreign affairs, finance, education, transport, travel and tourism, public works, water and sanitation, environment, social protection and agriculture. The aim is to leverage resources and efforts to ensure that every sector of government and society takes ownership of the response, participates in it and helps prevent transmission through sector-specific and general measures, including promoting hand hygiene, respiratory etiquette and individual-level physical distancing.
Other factors outside public health
In addition to the public health risk posed by the COVID-19 pandemic, countries should also take into account other economic, political and social considerations when deciding on resuming international travel. Such considerations should be assessed with relevant stakeholders and appropriate experts and authorities. Relevant guidance can be found, for example, through the United Nations Development Programme (UNDP) , the World Tourism Organization (UNWTO) , the International Labour Organization (ILO) , the International Maritime Organization (IMO) , and the World Bank .
Some United Nations (UN) agencies that play key roles in supporting States in resuming international travels have launched concrete COVID-19-related initiatives in line with their agency-specific mandates with the active participation of States and other international organizations. This includes the International Civil Aviation Organization (ICAO), which developed guidance for resumption of international air travel (Take-off document)  in collaboration with other UN agencies and relevant industry partners.
4. REQUIRED CAPACITIES FOR THE MITIGATION OF IMPORTED CASES
Understanding that the mitigation efforts to curb COVID-19 ultimately fall on countries and territories at destination. Countries should have appropriate public health and health systems capacities, particularly at points of entry (ports, airports, ground crossings) to test, isolate and treat cases, and quarantine their contacts, and exchange information and data internationally, as appropriate.
4.1 Coordination and planning
Working across sectors is essential for the proper implementation of public health measures. The transport sector is central to travel operations, but the involvement of other sectors such as trade, agriculture, tourism and security are essential to capture all the operational aspects associated with the gradual resumption of international travels.
Although not specifically designed for the COVID-19 pandemic, tools for general capacity assessment for health emergency preparedness can be helpful. WHO has produced a tool outlining critical preparedness, readiness and response actions. 
4.2 Surveillance and case management capacity
Active epidemiological surveillance for case detection, case isolation, contact identification and contact follow-up are central to the effective management of the COVID-19 pandemic , . Suspect and confirmed cases should rapidly be isolated, and contacts of confirmed cases should be quarantined . Persons who are suspect or confirmed to have COVID-19 and contacts of confirmed cases  should not be allowed to travel.
Use of existing surveillance systems and laboratory capacity
The national surveillance system for COVID-19 would benefit from information shared through existing respiratory disease surveillance systems, such as those for influenza, influenza-like-illness or severe acute respiratory illness. A sufficient workforce of trained public health or community health workers for case detection and contact tracing, and integrated risk communication and community engagement including through social media to ensure population acceptance are key elements for effective surveillance. Countries should have sufficient laboratory testing capacity and a clear testing strategy to reliably identify cases and trace contacts, including among incoming travellers. WHO guidance on surveillance  and contact tracing  should be followed.
Some countries are already using or are considering the use of digital tools to support contact tracing efforts. These include mobile phones and apps for location tracking or proximity tracing, and/or for symptom reporting during the 14-day post-arrival period. Such technology cannot replace public health contact tracing but may be considered as an adjunct under specific conditions that WHO has recommended . Mobile phones and apps can be effective in identifying and informing travellers who may have been in contact with a person confirmed to have COVID-19 or a positive test for COVID-19 only if a large proportion of the general population uses such an app. For travellers, issues of compatibility and data sharing between countries need to be considered, should international contact tracing be warranted. Before adopting such digital tools, countries may want to consider legal and ethical aspects related to individual privacy and personal data protection .
International contact tracing
When a cluster or chain of transmission involves several countries, international contact tracing can be done in a coordinated and collaborative manner through rapid information sharing via the international network of National IHR Focal Points (NFPs). The NFPs are accessible at all times and can receive direct support from the regional WHO International Health Regulations (IHR) Contact Points. The contact details of all National IHR Focal Points and WHO IHR Contact Points in the regions can be found in the WHO Event Information System (EIS), which is accessible to national health authorities.
4.3 Risk communication and community engagement
It is essential to proactively communicate to the public through traditional media, social media and other channels about the rationale for gradually resuming international travels, the potential risk of travel and the measures required to ensure safe travel for all, including regular updates on changes in international travel, or COVID helpline to disseminate information and provide advice tailored to sub-national level situations This is essential to build trust in travel advice, increase compliance with health advice and prevent the spread of rumours and false information . Timely and accurate communication on changes in international travel should target the general public, travellers, operators of the transport sector, health authorities and operators in other relevant sectors.
4.4 Capacity at Points of Entry
Countries should maintain or strengthen, as necessary, their capacities at Points of Entry (PoE) for the COVID-19 response. These, include capacities for entry/exit screening; early detection through active case finding, isolation and testing of ill passengers (including supply of personal protective equipment at PoE); cleaning and disinfection; case management, including any necessary transportation to a medical facility; identification of contacts for contact-tracing; public information sharing on local policies for adequate hygiene and sanitation measures; physical distancing and wearing of masks; sharing of emergency phone numbers; and risk communication and education on responsible travel behaviour. Adapted procedures for handling baggage, cargo, containers, conveyances, goods and postal parcels should be available and clearly communicated. Countries also need to ensure capacities for ship inspection and issuance of ship sanitation certificates within the framework of the IHR. WHO guidance on the management of ill travellers at points of entry  and other relevant guidance, such as operational considerations for airlines and other transport operators , should be followed.
WHO recommends a comprehensive approach to supporting and managing travellers before departure and on arrival, which includes a combination of measures for consideration before departure and on arrival.
General advice for travellers includes personal and hand hygiene, respiratory etiquette, maintaining physical distance of at least one metre from others  and use of a mask as appropriate . Sick travellers and persons at risk, including elderly travellers and people with serious chronic diseases or underlying health conditions, should postpone travel internationally to and from areas with community transmission.
Exit and entry screening includes measures like checking for signs and symptoms (fever above 38°C, cough) and interviewing passengers about respiratory infection symptoms and any exposure to high-risk contacts, which can contribute to active case finding among sick travellers. Symptomatic travellers and identified contacts should be guided to seek or channelled to further medical examination, followed by testing for COVID- 19. Confirmed cases should be isolated and offered treatment as required. Temperature screening alone, at exit or entry, is likely to be only partially effective in identifying infected individuals since infected individuals may be in the incubation period, may not express apparent symptoms early in the course of the disease, or could even dissimulate fever through the use of antipyretic medications. Where resources are limited, entry screening is advisable and should be prioritized for passengers arriving on direct flights from areas with community transmission.
In addition, passengers may complete a form informing health authorities about their possible exposure to cases within the last two weeks (contact with patients among health care workers, visits to hospitals, sharing accommodation with a person sick with COVID-19, etc.). The form should include relevant contact details of passengers who may need to be reached after travel when, for instance, they are identified as a possible contact of a case. It is recommended that such a form be filled during the flight to avoid crowds at the arrival. Authorities may also require arriving passengers to download and utilize a national COVID-control App.
Crowd control should be put in place to prevent transmission in areas where travellers gather, such as areas for interviews.
Laboratory PCR testing (molecular testing for SARS-CoV-2) immediately prior to departure or on arrival may provide information about the status of travellers. However, laboratory results should be interpreted with caution, since a small proportion of false negative and false positive results may occur. If conducted, testing should be accompanied by a comprehensive COVID-19 follow up, for example, by advising departing travellers who have been tested to report any symptoms to local public health authorities. If the testing is conducted on arrival, all travellers should be provided with an emergency phone number in case symptoms develop. A relevant case management protocol should be followed in case of a positive test.
The use of “Immunity certificates” for international travel in the context of COVID-19 is not currently supported by scientific evidence and therefore not recommended by WHO . More evidence is needed to understand the effectiveness of rapid SARS-CoV-2 antibody tests. For more information, please refer to WHO scientific brief “Immunity passports” in the context of COVID-19, which will be updated as new evidence becomes available. Beyond the scientific considerations, there are ethical, legal and human rights aspects related to privacy of personal data, medical confidentiality, potential risk of falsification or engagement in risky behaviour, stigma and discrimination.
Travellers should self-monitor for the potential onset of symptoms on arrival for 14 days, report symptoms and travel history to local health facilities and follow national protocols. In accordance with WHO guidance on contact tracing in the context of COVID-19, contacts of confirmed cases should be quarantined or asked to self-quarantine as part of national response strategies .
If countries choose to implement quarantine measures for all travellers on arrival, they should do so based on a risk assessment and consideration of local circumstances. They should also follow WHO guidance on quarantine of contacts in the context of COVID-19 .
Countries must follow the special considerations for travellers under the IHR (2005), including by treating travellers with respect for their dignity, human rights and fundamental freedoms and minimizing any discomfort or distress associated with any health measures applied to them.
Countries shall not charge travellers for measures required for the protection of health, including (a) examinations to ascertain their health status; (b) vaccination or prophylaxis on arrival (not published 10 days earlier); (c) appropriate isolation or quarantine; (d) certificates specifying the measures applied; or (e) applied to baggage accompanying them.
5. MONITORING AND EVALUATION
Countries should regularly reiterate the risk assessment process and review the capacity of their public health and other relevant sectors while gradually resuming international travels. In this process countries should also consider new knowledge about the virus and its epidemiology by consulting updated WHO scientific briefs.