If you're already enjoying traveling again, you are probably also wondering when it is safe to fly. A research letter examining the effects of COVID-19 infected passengers on a flight in March attempted to answer that question. The case series published in JAMA on August 18 is based on the experiences of 102 passengers who were on a flight from Tel Aviv, Israel to Frankfurt, Germany.
Twenty-four passengers on the flight were from the same tourist group. A week before their flight, they were unknowingly exposed to someone who later tested positive for COVID-19. Before the flight, none of the travelers appeared to be sick. The researchers said of the 4-hour and 40-minute flight, "No measures to prevent transmission (such as wearing masks) were used."
The researchers tested the tourist group when they landed in Germany and found that of the 24, 7 were positive. Four people became ill during the flight, two developed symptoms and one, although positive, was asymptomatic. The group, which made up a quarter of the passengers, exposed the other passengers on the plane. The research team was able to track most of the other passengers and found 2 confirmed COVID-19 cases which they attributed to the tourist group, although they weren't sure if an infection had occurred on the plane. "These transmissions could also have taken place before or after the flight," they wrote. The researchers drafted the plane's seating plan and found that the two passengers who developed COVID-19 sat no more than two rows away from the infected tourists.
Arnold Barnett, PhD, professor of statistics at MIT, published his estimates for the chances of getting COVID-19 onto an airplane in another study, "What Happens In The Air?" He found the odds were "1 in 4,300 for full flights and 1 in 7,700 if the middle seats are kept empty". Dr. Barnett also tried to calculate the risk of death from an airborne COVID-19 infection. He found that anywhere between 1 in 400,000 and 1 in 600,000 passengers would die. His article has yet to be reviewed by experts.
As with any activity, flying is risky during the pandemic, but it appears to be a calculated risk. Dr. Barnett found that the risk decreased when the plane was not at full capacity.