SARS-CoV-2 variant Delta rapidly displaced variant Alpha in the United States and led to higher viral loads. Bolze et al
Description
We report on the sequencing of 74,348 SARS-CoV-2 positive samples collected across the United States and show that the Delta variant, first detected in the United States in March 2021, comprised the majority of SARS-CoV-2 infections by July 1, 2021, and accounted for >99.9% of infections by September 2021. Not only did Delta displace variant Alpha, which was the dominant variant at the time, it also displaced the Gamma, Iota and Mu variants. Through an analysis of quantification cycle (Cq) values, we demonstrate that Delta infections tend to have a 1.7x higher viral load compared to Alpha infections (a decrease of 0.8 Cq) on average. Our results are consistent with the hypothesis that the increased transmissibility of the Delta variant could be due to the Delta variant’s ability to establish a higher viral load earlier in the infection compared to the Alpha variant. The dataset attached includes the raw numbers to regenerate all of the figures from this paper. Specifically, the different tabs correspond to: Data_Figure_1A, related to Figure 1A Data_Figure_1B, related to Figure 1B Data_Figure_1C, related to Figure 1C Data_Figure_2A, related to Figure 2A Data_Figure_2CD_S1CD, related to Figures 2C, 2D, S1C, S1D