I suppose it would make pretty good logic that if it will slow the progression of a current disease it might also provide prevention properties. But this particular researcher (he is a young PHD researcher as well as a 4th year medical student at Harvard Medical School) was addressing some current mouse studies as well as some case reports and some small human studies. 

What I say doesn't mean much, but Norwitz seems to be a pretty bright young researcher. He might be on to something.