My point is that it is theoretically possible but practically impossible. Rare events sometimes happen. With no background in biology, I can't say what the ac

My point is that it is theoretically possible but practically impossible. Rare events sometimes happen. With no background in biology, I can't say what the actual probability is. Is the chance of a single virion infecting a cell 1 in a sextillion, or only 1 in a million? In either case, it is still possible, as far as I understand the definition of the word 'possible'.