[acqq]

> the theory that some strains in Iceland are ineffective

I don't see any support at all for that theory though. It is also known that "X show no symptoms" could mean many things, depending who says it and when, and certainly doesn't prove anything alone, only in context, compared to something else, and only when comparison is fair.

For example, from many old news, those "with no symptoms" eventually had the symptoms, it was just that the tests were positive before they developed the symptoms. Second, it is now known that the probability of "having" symptoms is very dependent on the age of the person.