Have we learned more about air travel and coronavirus? Is it safe?

For Bay Area residents with relatives nearby, visiting during the pandemic comes with extra precautions: masks, backyard meals with physical distancing, and no hugs or handshakes. But for those with loved ones a flight away, the decision is more complicated. It means considering the threat of infection while flying versus the pain of missing funerals, births, and graduations. And considering your own infectious threat to those you are visiting and how much of a quarantine to self impose.
Airline travel has changed dramatically over the last 6 months, with international airlines operating just 2-4% of its usual number of flights, and most domestic airlines limiting capacity (although often by only 30%). To lure travelers back, airports and airlines are taking measures to mitigate risk, like physical distancing markers, providing masks, new cleaning procedures, boarding protocols, and suspending food and beverage service to minimize contact between crew and passengers. Mask requirements have now finally been enacted by all major airlines. And on United, Delta, and JetBlue, those not complying are added to a No-Fly list and banned for a period of time.
“Flying is an accumulation of a bunch of things that in general imply higher risk,” says Bob Wachter, chair of UCSF Medicine, in a June SF Chronicle article . “It is staying in fairly close contact with a whole lot of people you don’t know, it is doing that indoors, it is doing that for long periods of time.” There’s the ride to the airport, security lines, using a public restroom, buying a snack and walking down the jetway to board — a process bringing you in contact with strangers and the surfaces they touch every step of the way. None is particularly dangerous on its own, but each adds to the overall chance of exposure.
And there is reason to be nervous. A study published August 18th discovered two passengers who likely acquired COVID-19 on a 4 hour flight from Tel Aviv, Israel, to Frankfurt, Germany, carrying 102 passengers. On that flight was a tourist group of 24 people who had been in contact one week earlier with a hotel manager, later diagnosed with COVID-19. Seven of those tourists tested positive for the virus upon arrival in Frankfurt — as eventually did two passengers who were seated within two rows of them. None wore masks during the flight.
This study is somewhat unique in that health authorities from both countries successfully followed all involved individuals and completed thorough tracing protocols. Similar data is limited for most flights. But there are some data and case studies available, and they seem to suggest a low infectious risk from flying. Specialists in air travel and disease agree with this reassuring, albeit preliminary, perspective.
In an NPR interview with Lin Chen, an infectious disease and travel medicine doctor, and president of the International Society of Travel Medicine, she said a review of the available data, although varied, showed that the overall rate of infection from air travel is “very, very low.” She points to a January flight from China to Canada and another flight from New York to Taipei, each with one symptomatic COVID-19 passenger who did not infect anyone else on board.
Researchers theorize several reasons for this: deliberate underbooking by airlines, masks and symptom-checks, or just really insanely efficient ventilation systems present on most modern airplanes (15-20 HEPA-filtered air exchanges per hour). But Dr. Chen emphasizes that we don’t really know: “Testing may have been suboptimal in January [to] March, and we may have missed some cases that were acquired in-flight.” Or perhaps the low numbers simply reflect the low volume of travelers. If passenger volume increases and airlines add back flights, Chen says we may see more cases and exposures, especially as testing access improves.
If you do fly: Smart precautions for air travel
Minimize contact: look for an airline that has blocked middle seats, fly at less crowded times, book a window seat so you’re in proximity to fewer people during the trip. Carry on: the fewer people who touch your bag the better. BYO-everything: bring your own snacks and water bottle. Sanitize: TSA allows up to 12 oz of liquid hand sanitizer in carry-ons. Clean your hands every time you touch a public surface. Avoid the tiny airplane bathroom: go before you board. Wipe down: bring alcohol wipes to give your seat area a thorough cleaning. Mask up: wear a mask the entire time, and notify flight attendants if others are not wearing theirs. Add a face covering like a plastic shield for even more protection.

(Sky Pittson, MD, September 2, 2020)