Seroprevalence of SARS-CoV-2 antibodies in Seattle, Washington: October 2019-April 2020.
Denise J McCullochMichael L JacksonJames P HughesSandra LesterLisa MillsBrandi FreemanMohammad Ata Ur RasheedNatalie J ThornburgHelen Y ChuPublished in: PloS one (2021)
The absence of SARS-CoV-2 antibody-positive samples in October 2019 through mid-March, 2020, provides evidence against widespread circulation of COVID-19 among healthcare users in the Seattle area during that time. A small proportion of this metropolitan-area cohort had been infected with SARS-CoV-2 by spring of 2020.