months before the delta variant entered the united states. how safe is that in these times with delta, dr. fauci? >> again, i think what we have to do, craig, is make sure that everything you talk about with delta is always a bit more risky than it is with the others, but there haven't been head to head comparisons. so i really can't give you a scientifically based answer based on a head to head comparison. i can only tell you that you've always got to be more careful when you're dealing with transmissibility when you're dealing with delta because without a doubt, the one thing we do know is that delta is more transmissible. getting back to the original question you asked, that type of approach of daily testing has worked in other situations as opposed to when you get a child infected, you've got to quarantine everyone who's come into contact with them. so that pilot study you mentioned i believe is an