Figure 8.

Percent progress toward herd immunity in each of the 50 US states. Percent progress $𝒫$ indicates the fraction of immune persons required for herd immunity. $𝒫$ was calculated using Equation (2). Black bars (Panel (A)) correspond to the first scenario (i.e., $f_r$ estimated as the number of detected cases divided by population size), gray bars (Panels (A,C)) correspond to the second scenario (i.e., $f_r$ estimated as the number of detected cases within a population divided by the population size, adjusted for lack of detection of undiagnosed SARS-CoV-2 infections), black bars (Panel (B)) correspond to the third scenario (i.e., $f_r$ given by seroprevalence survey results), and gray bars (Panels (B,D)) correspond to the fourth scenario (i.e., $f_r$ given by seroprevalence survey results adjusted for lack of detection of asymptomatic cases). Estimates for $𝒫$ are sorted by state from largest to smallest values according to the second scenario (Panels (A,C)) and the fourth scenario (Panels (B,D)). North Dakota was omitted from Panels (B,D) because a recent estimate of seroprevalence was not available at Ref. [25]. States are indicated using two-letter US postal service state abbreviations (https://about.usps.com/who-we-are/postal-history/state-abbreviations.pdf (accessed on 19 September 2021)).