Self WH, Tenforde MW, Stubblefield WB, Feldstein LR, Steingrub JS, Shapiro NI, Ginde AA, Prekker ME, Brown SM, Peltan ID, Gong MN, Aboodi MS, Khan A, Exline MC, Files DC, Gibbs KW, Lindsell CJ, Rice TW, Jones ID, Halasa N, Talbot HK, Grijalva CG, Casey JD, Hager DN, Qadir N, Henning DJ, Coughlin MM, Schiffer J, Semenova V, Li H, Thornburg NJ, Patel MM. Seroprevalence of SARS-CoV-2 Among Frontline Health Care Personnel in a Multistate Hospital Network - 13 Academic Medical Centers, April-June 2020. MMWR Morb Mortal Wkly Rep. 2020 Sep 04; 69(35):1221-1226.