The International Air Transport Association (IATA) has urged governments to make data-driven decisions to manage the risks of Covid-19 when reopening borders to international travel. Strategies without quarantine measures can enable international travel to restart with a low risk of introduction of the disease to the travel destination.

“Data can and should drive policies on restarting global travel that manage Covid-19 risks to protect populations, revive livelihoods and boost economies. We call on the G7 governments meeting later this month to agree on the use of data to safely plan and coordinate the return of the freedom to travel which is so important to people, livelihoods and businesses,” said IATA director general Willie Walsh.

Vaccinated travellers

Evidence continues to show that vaccination protects travellers from serious illness and death and carries a low risk of introducing the virus into destination countries. The European Centre for Disease Control and Prevention (ECDC) issued interim guidance on the benefits of full vaccination stating that “the likelihood of an infected vaccinated person transmitting the disease is currently assessed to be very low to low”. Meanwhile, a Public Health England study has concluded that two doses of the Covid-19 vaccines are highly effective against variants of concern.

Testing for unvaccinated passengers

One challenge is the potential of barriers to travel for unvaccinated people, which would create an unacceptable exclusion. Data from the UK NHS regarding international travellers arriving in the UK (with no reference to vaccination status) shows that the vast majority of them pose no risk for the introduction of Covid-19 cases after arrival.

Between 25 February and 5 May 2021, 365,895 tests were conducted on arriving passengers to the UK. These were PCR negative before travel. Only 2.2 per cent tested positive for Covid-19 infection during universal quarantine measures after their arrival. Of these, over half were from “red list” countries, which were considered very high risk. Removing them from the statistics would result in test positivity of 1.46 per cent.

Of the 103,473 arrivals from the EU (excluding Ireland), 1.35 per cent tested positive. Three countries, namely Bulgaria, Poland and Romania, accounted for 60 per cent of the positive cases.

Airbus evaluates whole journey risk

IATA has teamed up with Airbus and Boeing to demonstrate potential methodologies to manage the risks of Covid-19 to keep populations safe while restarting global connectivity. Focusing on risks across the whole journey, Airbus considered more than 50 variables (such as number of confirmed cases and fatalities per country, Covid-19 testing strategies, traffic statistics, flight length, time spent in airport terminals, provision of on-board catering and air conditioning) in its model. Assumptions for the model are based on over a dozen data sources, including the US Centers for Disease Control and Prevention and the World Health Organisation.

Results of the model were cross-referenced against data collections from actual results and observations from travel. Using current Covid-19 incidence data and not making any consideration for vaccinated travellers (which would only lower the risk of infections), example findings include:

• High to medium incidence – Latin America & Caribbean (292 cases/100,000 population) to Canada (95 cases/100,000 population): Assuming the same traffic as in 2019 and without any testing, we expect that the local incidence in Canada would increase by just over 1 case / 100,000 population due to the imported cases over 14 days. With a single PCR test before travel, this number falls to less than 1 case/100,000 population.
• Medium to medium incidence – Europe (111 cases/100,000 population) to US (81 cases/100,000 population): Assuming the same traffic as in pre-COVID-19 and without any testing, the Airbus model predicts that air travel over 14 days would add less than 1 imported case/100,000 population to the local incidence in the US.
• Medium to low incidence – Europe (111 cases/100,000 population) to Singapore (8 cases/100,000 population): Conservatively assuming the same traffic as in 2019 and without any testing, we predict that over 14 days air travel would add over 1 imported case/100,000 population to the local incidence in Singapore. With a PCR test before travel, this number falls to less than 1.

The Airbus model demonstrates that the risk of virus transmission and translocation can be significantly reduced by adopting data-driven screening and protection measures.

Efficacy of testing strategies

Boeing modelling and analysis shows screening protocols offer an alternative to mandatory quarantines for many travel scenarios. The model evaluates the effectiveness of passenger screenings and quarantines in countries around the world. It accounts for various factors including Covid-19 prevalence rates between origin and destination countries, the efficacy of PCR and rapid antigen tests, and the disease timeline (how the disease progresses) for infected passengers.

The modelling revealed several key findings: data shows there are screening protocols as effective as a 14-day quarantine; screening protocols lower the risk to the destination country; and screening is most beneficial for travel from higher to lower prevalence areas.

The passenger screening model and findings were validated using actual travel testing data from Iceland and Canada. Boeing is now modelling scenarios with vaccinated travellers. As data on new Covid-19 variants becomes available, it will also be incorporated into the model.