laurie garrett, welcome. so there is some good news today from the w.h.o. about guinea and liberia. do you size up the situation there, having just come back? >> well with, certainly in liberia, the american presence has made a difference. the staggering capacity of the liberians themselves, the way they have organized, have made a difference and, indeed, that epidemic which was doom and gloom in september has plummeted. now, the danger is to get cocky and think, okay, it's all over, we can all go back to behaving exactly as we did before ebola emerged and, obviously, liberia made that mistake before in april thinking it had this small intrusion from guinea and that a it was over and everybody could go back to business as usual. of course, we know what happened after that. guinea, i have not been in guinea, but i can see that the data we have so far looks promising. that's a country where the president himself has equally engaged in fighting the epidemic. sierra leone is another story. >> woodruff: well, what about the challenges in sierra leone, based on what you saw? >> it's a re