FIG 4.

(a and b) Variant dynamics determined by Pangolin using GISAID samples from the state of Illinois in the United States (n = 20,165) (a) and from the United States (n = 1,187,412) (b). (c and d) Focusing on the spike protein mutations in the Delta variant, we showed the sensitivity and specificity of assigning the Delta variant based on the presence of each mutation in GISAID samples from Illinois (c) and the United States (d). (e and f) Estimated assignment of GISAID samples from Illinois (e) and the United States (f) to variants using the primer designed to target mutation S:P681R.