symptoms they can be very helpful. you want to call your doctor if that happens. >> do you think science is keeping up with how quickly the virus seems to be changing and? i mean who is winning, the science or the viruses? >> well you know i'll tell you every year sometimes it's a little bit different. as scientists they make their best guesses for figuring out which strains are going to be predominant for the next season. and there's a lot of science and math and brains that go behind trying to make that prediction. but the truth of the matter is that sometimes we get it right and sometimes it's off a little bit. that's why all this prevention is very helpful. and still, yes, get the flu shot. that's very important. >> dr. jennifer kaudle. good advice. we want to get to poppy harlow for the day's other top stories. new york city about to ring in 2015 with a huge party. but it will happen under intense security. heavily-armed counterterrorism teams, bomb-sniffing dogs