school and trying to get all families to participate in surveillance programs so we can detect disease early and mitigate big outbreaks. i think if we are willing to be really on top of things, then kids can stay in school and stay healthy there. >> yeah. all right, dr. esther chu, thanks so much. we sure do appreciate it. >> my pleasure. as the nation confronts this covid surge during the holiday travel season, the new possibility hanging over future flights. president biden now says he would impose vaccine requirements for domestic travel if his medical team recommends it. a short time ago, his chief medical advisor appeared to discuss it. >> everything is always discussed and we discuss it regularly. right now we feel the masking requirement and the degree of filtration on a plane is sufficient to keep people safe.