If flying is so dangerous right now, why do airline workers have lower overall infection rates than the general population? This is one of many questions being asked, as the world weighs travel restrictions, and the devastating effects covid-19 are having not only on the population, but economies worldwide.

The CDC just released a lengthy report on covid-19 transmission on board long haul flights from the days before masks were made mandatory onboard, and even then, transmission wasn’t nearly as bad as many would think.

But let’s start with the sobering reality. As surmised in the study: the risk of covid-19 transmission on planes is “real”. Also in reality, the risk of covid-19 transmission is real virtually anywhere that isn’t your own personal space, and therefore a trip to a local coffee shop may be a level of risk that’s understandably unacceptable for many.

For many people, travel is a risk too great right now, and there’s zero judgement on that front. People must assess risk as it applies to them, using as much scientific data as possible. Many travelers will be encouraged by the report in the sense that finding a spreader event was noteworthy, rather than “not” finding being of note.

Covid-19 Transmission On Long Haul Flights

The CDC studies examined a variety of flights from February, March and April, during peak covid-19 infection periods, and tested and traced not only passengers on board, but nearly all close contacts prior to, and after the flight.

Notably, the study followed these flights in February, March and April, long before masks were made mandatory or used at all, and before airlines stepped up cleaning measures.

Perhaps crucially, no pre flight covid-19 testing for international travel was in effect at this point either, and could have made all the difference in the worst case results. For symptomatic travelers, access to covid-19 testing was also scarce at the time, and in many cases, full symptoms hadn’t been addressed to the public yet.


The tl:dr story is that a flight had covid-19 spread to other passengers during this time, but others, even ultra long haul flights did not.


On a 15 hour flight from China to Canada, one person was known to be infected with covid-19 during the journey, but is not believed to have infected anyone on board the flight. After testing and tracing, not a single other person is known to have contracted covid-19, though limitations are noted. The CDC report states…

In January 2020, no secondary cases were detected after a 15-hour flight to Canada with a symptomatic person with COVID-19 on board (29), although contact tracing and monitoring were limited (30). Similar results with similar limitations have been reported from flights arriving in France (31,32) and Thailand (33) in January and February.

CDC Report

Basically, before masks on board became a thing and airlines started handing out sanitizing kits for your seat and belongings, a variety of flights had infected passengers and after exhaustive research, the best conclusion was that no other flight passengers became infected on the majority of sampled flights.

The study woefully omits any recent data on flights in the following months since health and hygiene measures were introduced on board. A central focus of the CDC study was instead an outlier of spread from a flight in March, during the height of viral intensity in which a passenger knowingly put others at risk, and did.

Of the 5 main flights studied by the CDC, only one had defined covid-19 spread. A sixth flight from Singapore was also examined, where 16 covid-19 infected passengers were on board, but are believed to only have infected one additional person during the trip.

The flight from London to Hanoi in early March saw one passenger infect up to 16 people is believed to be the worst covid-19 spreader event in air travel studied. Those who were infected were almost all within close proximity to the spreader for the flight, which is legitimate reason to add pause, for some.

The passenger, which the CDC believes to be the “Case 1”, did not wear a mask or limit their movements while on board. Somewhat buried in the CDC report, the person was also knowingly symptomatic when they embarked on their travel journey, and ignored all warnings not to travel despite experiencing severe cough, shortness of breath and fever prior to flight.

Sunset aerial view through airplane window over wings. Flying at sunset and looking out of the window and enjoying the panoramic view. Travel and transportation concepts

The person was also in direct contact with someone who had just been in a highly infectious area, which is why country efforts to require covid-19 testing or additional quarantine restrictions for flights embarking from certain departure points adds a vital level of security.


Effectively, the spreader on this flight lied at check in when questioned about any of these symptoms, or their contact with people from high risk areas. In the least surprising news of 2020, people simply can’t be trusted to self isolate or cancel plans, no matter how much we wish it not to be that way.


Country or airline insistence on mandating recent negative covid-19 tests prior to flight could absolutely help in further mitigation of any travel related risks. Both Dubai and Emirates currently require a negative covid-19 test prior to flight, and before entry into the UAE, and after months of tourism has yet to experience a significant spike in cases. In Bahrain, of 713 new cases, 4 were believed to be travel related.

The airline doubled down by offering all passengers up to €150 in covid-19 related coverage, even for destinations beyond where they fly with Emirates for a period of 30 days. Virgin Atlantic and Etihad recently followed, with their own complimentary covid-19 cover for passengers.

But, what about short haul flights?

Short haul flights were recently hypothesized by MIT studies to carry a chance of covid-19 infection of between 1:4400 – 1:7700. The study gained traction with a separate new study suggesting cabin crew and customer facing airline staff in the USA have a .08% instance of covid-19 infection, compared to 2% for the general population.

Rather than being worse off for covid-19 infection, the data puts customer facing airline employees more than a single percentage point less likely to become infected.

Health officials currently recommend at least one fresh mask for every 4 hours of potential exposure, so if you’re taking a 10 hour flight, and have 4 hours of transit and airport time, plan to bring 14 hours worth of masks on board. That’s four masks, by the way. Regular hand washing and sanitizing of surfaces is also crucial.

The CDC report is far from a happy go lucky endorsements for a return to travel. However, the relatively low instance of new infection on flights, even in March before face masks, sanitizing products or mandatory covid-19 testing restrictions were added on board is encouraging. Use widely accepted available data to create your own risk assessment in travel.

For many, it’ll be a while before a long haul flight is appealing, either due to the risk or the restrictions, but for those who do travel responsibly it could be a lot worse right now.

HT: View From The Wing

Gilbert Ott

Gilbert Ott is an ever curious traveler and one of the world's leading travel experts. His adventures take him all over the globe, often spanning over 200,000 miles a year and his travel exploits are regularly...

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5 Comments

  1. Thanks, but no-one is trusting the CDC right now, or anyone from this administration, which includes the Surgeon General. Maybe cite some scientific papers?

    1. I did? I too am disenchanted with the CDC’s clarity and many things of this administration, but the CDC study cites many papers from other governments, which mainly bolster the position of low spread levels on flights. If interested, the linked studies (bottom paragraphs) of the CDC paper are the most interesting reads and offer greater detail on the flights without spread, or where 16 people known to be infected before flight infected only one during.

  2. I don’t trust the leadership in our health agencies with the lone exception of Fauci who is not perfect himself but is a great transparent leader who is willing to admit his mistakes. Additionally I know from working 32 years in the federal government there are many loyal and brilliant workers who are dedicated to the public they serve and are committed to doing the right thing no matter who is their boss. So these studies are helpful and I read them in that spirit.

  3. As of right now, the CDC is not trustworthy due to them becoming highly political and being tightly controlled by the current administration versus actual science. Unfortunately they are not a source of truth, but one of propaganda.

    Regardless of that, I ask this simple question – why do people need to always keep distance everywhere including the airport while at security, the gate area, the boarding, even the jet way – yet sit shoulder-to-shoulder next to strangers for hours at a time and that is ‘ok’? In particular in a densely packed small space. If you picture people standing in a small space directly next to each other (6 across shoulder to shoulder) in the airport it would be rather shocking to see the lack of distancing they are able to maintain. Now wrap them up in a small fully enclosed space and it gets even more drastic.

    It’s just comical to me how even some chairs at gate areas are blocked off to maintain distances from each other to end up sitting directly inches (at best) next to each other for hours on end. It just makes zero logical sense that it’s ok to be that close in a small enclosed space, but totally not ok in a much bigger wide open space. I simply cannot put any logic to that.

    1. I think the idea is eliminate risk where possible. Social distancing isn’t easily possible on planes, but it largely is in airports. You may be in close proximity to a few passengers on a plane, but adding extra elements of risk by rubbing elbows with entirely different sets of travelers at each airport juncture doesn’t help. Makes pretty good sense to me. It’s also easier to enforce masks, and to control cleaning environments on planes. I’ve witnessed cleaning measures and on long haul they really are robust now. Long may they live.

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