protection against the first two shots are going to need a third. i think we need to see the data from the cdc and how they justify that and not rely on preprinted and other data from israel and other places. you want to be sort of forecasting and seeing around the curves here but the data really has to mean something if they're going to make these big decisions. >> interesting. thank you very much. it is great to see you. other breaking story. the situation in afghanistan. evacuation flights have resumed after u.s. troops regained control of the kabul airport and we've now learned from the defs department that there will be 4,000 troops in the ground by the end of today. cnn chief correspondent jeff zeleny is live at the white house with more on this. jeff, a lot and some more detail coming from the pentagon about what they're doing now kind of to make up for what has