- MIT researcher Dr. Arnold Barnett said the risks of infection on planes are likely to be higher now than they were earlier in the pandemic.
- BA.5 variant infection and immune evasion present further risks when traveling.
- Although there is no longer a federal mandate for a mask on planes, experts say wearing a mask can provide protection.
In January 2021, passengers on a full two-hour flight had a 1 in 1,000 chance of contracting COVID-19, according to a study published July 2 in Health Care Management Science.
Researchers from the Massachusetts Institute of Technology used COVID-19 infection rates from June 2020 to February 2021, along with data on airborne virus spread, to model the risk of contracting COVID-19 at different passenger capacities during the study period. The study notes that from about December 2020 to January 2021, passengers were more likely to contract COVID-19 while flying.
Study co-author Dr. Arnold Barnett, an MIT professor who specializes in aviation safety, told Insider that the risk of infection on US planes is likely to be “much higher” now, due to a lack of mask mandates on planes and more flights.
Studies show the importance of seat proximity
Omicron subvariant BA.5 is the predominant COVID strain in the United States, and many of the new cases are re-infection, according to Insider’s Hilary Brueck and Natalie Musumeci previously.
People are more likely to contract COVID-19 indoors, according to the Centers for Disease Control and Prevention (CDC), especially without proper air filtering or masks. But commercial aircraft, such as the Boeing 737 or Airbus 320 used in this study, are equipped with high-efficiency particulate air (HEPA) filters, which reduce the risk of transmission, according to a 2020 report from the Harvard School of Public Health.
A small study published in November 2020 in the Journal of Emerging Infectious Diseases followed 217 passengers on a 10-hour commercial flight, when the mask mandate was still in effect, and found that 16 people tested positive for the virus in the days following their arrival. The study suggested that seat proximity was a significant predictor of transmission risk.
The risk of infection is likely to be higher now, according to a researcher at the Massachusetts Institute of Technology
MIT researchers found that while the risk of infection dropped to 1 in 6,000 on half-full flights in the summer of 2020, that number rose to roughly 1 in 1,000 in December 2020 and January 2021 on full-fledged aircraft.
Barnett told Insider that given the BA.5 variant infection, lack of mask mandates on public transportation, and planes more complete than they were in 2020, he expects infection risks to be higher now than what was found in the study.
He said the risk is likely to be greater on flights longer than two hours, or for travelers on multiple connecting flights.
Barnett said he flies regularly with an N95 mask and tries to stay away from other travelers when he can.
Experts say you should still wear masks while flying
As of April 2022, the Transportation Security Administration no longer enforces federal mask requirements for people traveling on airplanes.
However, both the CDC and other public health experts still recommend wearing a mask on planes. Gigi Gronvall, an epidemiologist and senior researcher at the Johns Hopkins Center for Health Security, previously told Insider that aircraft HEPA filters don’t always work while boarding or departing a plane, and they won’t always protect you from exposure.