to be as rapidly spreading as it did. reporter: even as americans face long lines for testing throughout parts of the country. biden urgen those vaccinated and boosted to maintain their poll say plans. you ve done the right thing. reporter: and americans listening, with the tsa reporting more than 2 million daily travelers for a fifth consecutive day, underscoring the challenge at hand for a white house attempting to assuage the most serious concerns for the vaccinated and boosted, and delivering dark warnings for those who have not gotten the shot. hospitals are full of people who made that mistake. so are graveyards full of people that have made that mistake. reporter: joe biden was candid. those who are vaccinated and boosted could return positive tests. that s just the reality of the omicron varniant. white house officials