Testing international travelers for COVID-19 is a bad idea

The Centers for Disease Control and Prevention (CDC) order requiring international travelers coming into the U.S. to provide either proof of a negative COVID-19 test within 72 hours of traveling or proof of recovery from COVID-19 makes no sense. 

On the practical side, asking travelers to find a way to get tested prior to their trip back to the country can be problematic in many countries. To put this into perspective — given the limited testing capacity — asking a visitor to get tested 72 hours prior to their flight and get the results back within this time frame would be near impossible in certain parts of the U.S. The U.S. administered just under 2 million COVID-19 tests per day on average in January 2021, or one test per day for every 160 people. Asking visitors to find a way to get tested with such a paucity of test availability makes the testing requirement unrealistic. 

On the health side, tests provide a single snapshot of a person’s COVID-19 status at the time when the test is administered. If a person does not self-isolate after the test, the value of the test result quickly diminishes. Moreover, with new variants of the virus circulating, like B.1.1.7, it is not clear how well some tests will detect them. A single negative test provides a false sense of comfort that a person is not infected. 

Airlines require face coverings on all flights — domestic and international — which long preceded President Biden’s executive order mandating face coverings within the air transportation system. This provides the most significant health benefit to all passengers and crew on a flight. The biggest risk is when passengers remove their face coverings when eating and drinking. Airlines should consider providing passengers the option of liquid meals that can be consumed with a straw under face coverings. Keeping mouth and nose barriers in place will have a more significant health benefit than requiring travelers to provide a negative test result prior to their flights.

Air travel continues to pose health risks. To date, one in seven Transportation Security Administration (TSA) officers have tested positive for the virus, in spite of the precautions taken at airport security checkpoints.  This indicates that virus transmission is occurring across the air system.   

Imposing unsustainable and impractical requirements on international travelers may also lead to retaliation from other countries requiring the same of travelers into their countries. The U.S. ranks first in the world in both the number of COVID-19 cases and the number of COVID-19 cases per capita amongst countries with a population of more than 12 million. The greatest virus transmission risk may be with people departing the U.S., not those coming into the country.     

Widespread vaccination provides the best pathway to jumpstart air travel. All airline workers and TSA officers are essential workers and should be vaccinated as soon as sufficient vaccine supply is available.  Within months, once vaccines are widely available to the entire population, asking travelers to provide proof of vaccination rather than a negative COVID-19 test result has more benefits. 

Any ill-conceived mandate that imposes impractical requirements will do more harm than good.  Requiring airlines to follow the 72 hour test requirement is an example of the CDC overstepping their authority and asking for something that offers no benefits. The CDC has indicated that this requirement will not be required on domestic flights, with airlines rightly voicing their concerns. Let the airlines continue to maintain appropriate health risk reduction protocols for their benefit and the benefit of those who choose to fly.   

Sheldon H. Jacobson, PhD, is a founder professor of Computer Science at the University of Illinois at Urbana-Champaign. He applies his expertise in data-driven risk-based assessment to evaluate and inform public policy and public health.