Estimated SARS-CoV-2 Seroprevalence in the US as of September 2020

Abstract
The first severe acute respiratory syndrome 2 (SARS-CoV-2) infection in the US was identified in January 2020,1 followed soon after by reports of community transmission.2-5 The US remains severely affected by the coronavirus disease 2019 (COVID-19) pandemic, with more than 9 million cases and 230 000 deaths reported through November 1, 2020.6 With limited testing availability and mild and asymptomatic infections contributing to underascertainment of SARS-CoV-2 infections through passive case reporting,7-9 seroprevalence surveys are important for refining estimates of infection and transmission.10