Many can/will attest to the message that’s here.
Myself, I flew from Europe to the Americas last week, and was required to cover my mouth for the duration of the flight, unless eating or drinking.
I only covered up in the airports if I was asked to, BUT on the plane, even when I was dozing, and my scarf had come down, I was brought to by a not so happy stewardess. Took days to recover from that (two days alone with such strong head pain), and bloating lasted almost nearly a week. (I’m a healthy woman, who eats whole food, plant based, with good immunity).
Beyond common sense.