We have known for centuries that international travel plays a key role in the translocation of disease, but the ever-increasing speed, distance, and volume of modern travel has meant that the potential for the international spread of infectious diseases has never been greater. Travel routes, aviation networks, destination and departure locations, passenger numbers, and size and type of transportation are all important considerations.
Since its onset, the Covid-19 pandemic has profoundly changed the travel landscape: travel restrictions, pre-departure or on-arrival testing, and quarantine or self-isolation when entering a country are now commonplace. For the traveller and those advising travellers, the pandemic has emphasised the need for detailed preparation and consideration of many additional Covid-19 specific factors. The lack of international standards, with differing rules and regulations depending on your home base, destination country, nationality, or Covid-19 immune status, adds further complexity.
Pre-travel research and preparation
It has never been more important to make pre-travel preparations. Thorough research on the additional risks posed by Covid-19, which has to be interpreted in the context of destination-related policy, is paramount.
Travel risk assessments should now include the traveller’s personal risk of Covid-19. For example, do they have risk factors for severe disease, are they vaccinated, and how does vaccination impact on their risk? What will their Covid-19 exposure be during their journey, and how will their mode of transport impact on this risk? For air travel, airport location, passenger and flight volume, time spent in transit mixing with other travellers in transport hubs, onboarding and disembarking; size, seating, cleaning protocols, and air exchange and filtering all play impact on risk. Similar considerations will apply to sea travel, which is further complicated by the unique environment on ships and potential for amplification of infection.
Risk assessments will also need to evaluate the impact of Covid-19 in the destination country. For example, what are the local disease rates, how do they compare with rates at home, how reliable are the figures? What is the Covid security of accommodation and planned activities; what is known about the public health infrastructure; how has Covid-19 impacted health systems; what are the procedures for testing, contact tracing, isolation or quarantine, should a traveller test positive for Covid-19?
These questions have to be considered in the context of government policy, both at home and in the destination country. With a lack of international consensus on policy and guidance, understanding country requirements can be perplexing. Policy responses in countries will be informed by differing and competing priorities, with some countries having few restrictions, and others with extremely stringent rules. They are also subject to rapid change in response to evolving epidemiology or the detection of variants of concern. It is unsurprising, therefore, that travellers can find policy decisions illogical, unclear, or confusing, making planning and research essential. For the traveller, access to timely, reliable public resources with data that will help inform decisions is vital. UK resources such as the FCDO Travel Advice, and the National Travel Health Network and Centre’s TravelHealthPro website, as well as international resources such as the US Centers for Disease Control and Prevention, the World Health Organization (WHO), and the European Centre for Disease Prevention and Control, will provide an important starting point. For travellers with pre-existing health conditions or complex travel itineraries, seeking medical advice may also be advisable.
Vaccine passports and other certification
Vaccine certification for travel purposes is not new; proof of yellow fever and polio vaccination (i.e. the International Certificate of Vaccination or Prophylaxis) is required for certain destinations or specific circumstances under the International Health Regulations 2005, and proof of meningococcal immunisation has been a requirement for those travelling to perform the Hajj for many years. Understandably, therefore, the development of Covid-19 vaccines has introduced the notion of ‘vaccination passports’; seen by many as a way of allowing fully vaccinated individuals to travel more freely and with fewer restrictions. Some countries have indeed already implemented exemptions for fully vaccinated travellers from quarantine.
However, there remain significant challenges and ethical dilemmas associated with Covid-19 vaccine passports, as currently no international certificate framework exists. For example, a number of Covid-19 vaccines are in use, documentation of vaccination varies from country to country, and questions remain about efficacy and duration of immunity, and the impact of variants of concern. It is also unclear if vaccines not authorised in the destination country will be accepted. Concerns remain that inequitable access to vaccines means that resource-poor countries will be negatively impacted, and if passports are introduced, this could be interpreted as vaccination being compulsory for travel.
The format of any vaccination passport too is proving to be problematic: should it be electronic or paper-based, and if the former, what does this mean in terms of privacy and accessibility? As with other Covid-19 policy decisions, there is a need for global agreement, and while WHO does not currently endorse the use of proof of vaccination or immunity as a condition of entry into a country, work is underway to develop a digital vaccination certificate to establish a governance framework and standards for use at globally. Such a certificate would be a welcome initiative if supported by policymakers. However, this will take some time, and national initiatives, even with their associated difficulties, will inevitably be widely implemented in many countries.
The future of travelling with the risk of Covid
The Covid-19 pandemic has illustrated the critical role that travellers play in the spread of emerging infections, and the importance of their health in terms of global health security. Due to varying country requirements and restrictions, the need for pre-travel advice and interventions will rise, as will the need to communicate risk effectively to allow individuals to make the right decisions about their travel plans, how to protect themselves, when to seek advice, and to avoid panic that might arise due to sudden policy changes. This will necessitate travellers having the right information, delivered in the right way, managing the Covid-19 ‘infodemic’ and maintaining trust.
A number of unanswered questions remain, and evidence and developments will continue to evolve. The effect that the public health focus on Covid-19 has had on other communicable disease control is also yet to the seen. The impact of Covid-19 on travel will continue for some years, and in particular, challenges will remain in countries where health systems and access to vaccines may be more limited. Even with vaccination and better control, it is likely that non-pharmaceutical interventions will remain or may even become the norm. Travel and traveller behaviour is unlikely to revert back to the pre-Covid-19 era, and will inevitably need to be flexible. Those advising travellers will need to maintain current knowledge and keep up to date with changing evidence to help travellers negotiate the many new complexities that Covid-19 has created. Access to reliable and credible sources of advice, consistent messaging, and appropriate signposting to health professionals, will be key.