Highly unlikely though. Once it's in the sticky mucus at the rear of the nasal passage it's not going to just float out. It will almost certainly end up being discharged with the mucus in the usual ways, either blown or sneezed out into a handkerchief or discharged through the digestive tract.I am not sure about harmless.
If the virus hangs about in your nasal passage then it can be released into the air and infect others.
But if just present and loose in the nasal passage but not trapped in mucus, I'm sure that's not unusual now, given the very widespread presence of the virus in the population.
In any scenario I'm certain we are over recording due to the swab test's obvious deficiencies.
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