>> doctor, there's also lingering questions about the booster shot for eligible people who got johnson & johnson, so what booster should they get? and when should they get it? >> two months after you got your first shot of j&j, so for most americans who got the one shot, they're probably two months out already. i strongly encourage them to get a second shot of an mrna vaccine, to not get the second shot of johnson & johnson, but to sub it out for a mrna vaccine. it's very safe based on both our own experience and global experiences, but really shoots up your level of protection in a way that that second dose of j&j just does not. >> that's interesting. the biden administration, doctor, laid out plans to rope international travel, but it does include a vaccine mandate for foreign travelers, with the