the cdc says there's a high to very high risk of spread across europe. jeff zeleny is live from nantucket for us. pete muntean joins us from reagan airport. they moved very quickly. all of a sudden, by the end of the day, all of these travel restrictions were announced. what are your white house sources telling you now? >> reporter: gym, no question, just shortly after, moments after the world health organizationsh the who's showed that concern, and on vacation propresident biden is spending time with his family, issued the travel restrictions to begin monday morning for south africa and seven other african countries, really stopping people from flying here to the u.s. unless you're an american citizen. but the white house also saying they simply do not know enough