It's a natural and common extrapolation, but not one that I'd expect to see from a scientist, particularly a biologist. I can't see the original article due to

It's a natural and common extrapolation, but not one that I'd expect to see from a scientist, particularly a biologist. I can't see the original article due to the paywall, but I understand the the German plural is Viruses, as in English. All very odd.