A 'super spreader' was likely responsible for 16 positive coronavirus cases on one flight, according to a new study into how the infection spreads on planes.
The paper warns the current practice of keeping middle seats empty "seems to be insufficient" at preventing such outbreaks.
Researchers analysed 10-hour Flight VN54 from London to Hanoi, Vietnam, on March 2 - with the results now published by the US Centres for Disease Control and Prevention (CDC).
Two-hundred and seventeen passengers were on board with a 27-year-old Vietnamese woman in business class believed to have been the source of the outbreak, reports the Daily Star.
According to reports, a dozen fellow business class passengers later tested positive.
The study found that "seating proximity was strongly associated with increased infection risk", despite passengers being more spaced out than those in economy class.
"We conclude that the risk for on-board transmission of SARS-CoV-2 during long flights is real and has the potential to cause Covid-19 clusters of substantial size, even in business class-like settings with spacious seating arrangements well beyond the established distance used to define close contact on airplanes," the study said.
"As long as Covid-19 presents a global pandemic threat in the absence of a good point-of-care test, better on-board infection prevention measures and arrival screening procedures are needed to make flying safe."
The report recommended that "tightened screening and infection prevention measures," especially for those travelling from countries with known high coronavirus transmission, should be implemented in airports and on planes, and that mask-wearing should be made mandatory.
The travel industry has taken a massive blow during the pandemic due to the extensive restrictions around the world, with British Airways, EasyJet and Ryanair all announcing mass redundancies.
In an effort to keep business going, airlines have undertaken various hygiene measures to minimise the risk of coronavirus entering and spreading on an aircraft.
New protocols include temperature screening, more intensive cleaning and mandatory mask wearing for all passengers on board.
However the new study doesn't bode well for the efficacy of seat spacing, another common strategy being employed to ensure passengers don't get too close together.