What are the chances that someone will contract Covid-19 on a plane flight? A study led by Massachusetts Institute of Technology (MIT) scholars offers a calculation — for travellers on US domestic flights — for the period from June 2020 through February 2021. The study estimates that the probability of getting Covid-19 on an aircraft was:
MIT acknowledged that current conditions differ from the study’s setting. Masks are no longer required for US domestic passengers; in the study’s time period, airlines were commonly leaving middle seats open, which they are no longer doing; and newer Covid-19 variants are more contagious than the virus was during the study period. While those factors may increase the current risk, most people have received Covid-19 vaccinations since February 2021, which could serve to lower today’s risk, the release said.
“Still, the study does provide a general estimate about air travel safety with regard to Covid-19 transmission, and a methodology that can be applied to future studies,” it said.
The researchers amalgamated public health statistics about Covid-19 prevalence, data from peer-reviewed studies about Covid-19 contagion mechanisms, data about the spread of viruses on airlines generally and the spread of Covid-19 on international airlines, and some available industry data about seat-occupancy rates on U.S. domestic jet flights. They then estimated transmission risks on US domestic airlines through extensive modelling.
The researchers used a two-hour flight for their estimates because that is about the average duration of a domestic flight in the US. As their airplane settings, they used a Boeing 737 and Airbus A320, with a single aisle, three seats on either side, and typical capacities of about 175 passengers. Most such planes do have high-functioning HEPA air-purification systems, which help reduce the transmission risk of airborne illnesses.
The paper, ‘Covid-19 infection risk on U.S. domestic airlines’, appears this month in the journal Health Care Management Science.