Margaret Brennan talks with Illumina President and CEO Francis deSouza. Illumina is helping scientists around the world identify new strains of the COVID-19 virus and was part of the team that detected some of the first cases of the United Kingdom variant in the United States. deSouza tells Brennan that the United States is currently sequencing on average 0.3% of positive cases and that in order to get a good understanding of what's happening, “you really need to be sequencing about 5% of the positive cases as well as sampling the negative cases.”