omicron, public health officials continue to stress the importance of getting vaccinated. tonight, nearly 25% of americans have yet to get a first dose. what keeps me up at night around covid is the number of people who have not yet gotten their vaccine. it is absolutely our best way out of this pandemic. reporter: scientists here in the u.s. are also currently studying vaccine effectiveness against omicron. dr. fauci said today we could have those results in about a week. norah. o donnell: nikki battiste, thank you. well, let s go now to chicago where actor jussie smollett was back on the witness stand saying, there was no hoax. he is sticking to his story that he was the victim of an antigay and racist attack while prosecutors say he staged the whole thing to increase his fame and fortune. cbs charlie de mar has more from the courthouse.llet rned witness stand in his own defense, maintaining his