The young woman and her sister had traveled across Europe just as the coronavirus pandemic was taking off there, visiting Milan and Paris before heading to London.
When the woman left London on March 1, she had a sore throat and cough as she boarded a flight home to Vietnam. But no one noticed.
By the time she got off the flight in Hanoi 10 hours later, 15 other people who had been on the plane with her were infected, researchers reported Friday.
This story is one of two published Friday demonstrating how coronavirus can spread on airline flights, and suggesting that simply spacing people out a little will not fully protect them.
In another incident, passengers on a flight from Boston to Hong Kong appear to have infected two flight attendants.
Both cases involved long flights early in the pandemic, before airlines began requiring face masks.
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