In contrast to the US, the UK was able to detect the more contagious B.1.1.7 variant because it was sequencing about 10 percent of all patient samples. By the time the delta variant, B.1.617, emerged in May 2021, the UK was sequencing 60 percent of all patient samples.33 By comparison, the CDC had set as its initial goal getting five sequences from each state per week. When B.1.1.7 arrived in the US, the CDC was sequencing only 0.3 percent of patient samples. This
