testing positive for covid. >> many of the omicron cases interestingly are either without symptoms or minimally symptomatic. particularly the breakthrough cases. >> reporter: monday more than 7400 flights were delayed. and the seasonal rush is also creating a heavy demand on covid testing. >> all i can do is wait. several places is the same. >> reporter: testing locations are swamped with lines ramped around for blocks. and president biden conceding the steps he took earlier to scale up testing capacity have been insufficient in the wake of the omicron surge. >> we went there no over-the-counter tests in january to 46 million in october, 100 million in november and almost 200 million in december. but it is not enough. clearly not enough. >> reporter: the administration is preparing another 500 million free rapid at-home tests for