but at first holly elliot ignored that recommendation. >> i let my pride keep me from vaccinating my children. and i'm hoping that maybe other people will be able to overcome their own pride and make the right decision. >> reporter: the decision to vaccinate for more protection and for her, more peace of mind. hallie jackson, nbc news, los angeles. >> all of this raises a natural question. and we have a quick question here to our chief medical editor dr. nancy snyderman. do adults, does anyone need to get a booster shot in this environment? >> blanket recommendation, no. if you have not had measles, if you have not been vaccinated, then that's a reason to consider getting a booster, or obviously if you live in one of these areas where the outbreaks are then of course talk to your doctor about getting a vaccination. those are the things because we want people even adults protected. >> nancy, thank you as always. >>> tonight, the fbi is on the hunt for a person or persons behind a series of threatening messages on social media. they have led to at least 20 air scares on commercial flig