K, I very much agree with you on this observation, even if I do not know these figures precisely. But maybe people who were positive and seriously ill are much more careful and protect themselves better against new infections. That could explain the small number. On the other hand, people who tested positive without symptoms might not show symptoms even if they have a second infection. Or maybe there are many people who have never been tested, had no symptoms and have been positive twice over the months.
It would have to be very specific about finding people who had severe symptoms, were cured and how they react to a second infection.
