. >> sabrina sadiki at "the wall street journal". >> thank you for doing this. you have obviously signalled you are encouraged by the developments with the johnson & johnson vaccine. how does that get incorporated into the distribution framework? what messaging challenge might be posed by the lower effectiveness when compared to other available alternatives? >> i will take the first half. i will pass the second to dr. fauci. i think he does a very nice job explaining what is different and what's important about the differences. the short answer is it would help. obviously it would help. i want the public to understand that this administration is not getting ahead of the fda. we are not planning for facts that are not yet in evidence. the numbers and the dates we have talked about here are relative to the two vaccine and two dose regimen on the market. there would be some improvement should there be a third dose. i will tell you that, the expectation however should not be that that is an immediate, dramatic shift. the expectation should be that their commitment,