Northwell Health, Manhasset, NY, offered free SARS-CoV-2 antibody testing to its 72,000 employees—the first sizable, systematic testing of American healthcare workers’ serology—during the covid-19 pandemic.1 Northwell’s research arm, the Feinstein Institutes for Medical Research, and its Northwell Health Covid-19 Research Consortium (CRC) reported the results of the testing for healthcare providers (HCPs) from April 20 to June 23. Of the final consented sample of HCPs (40,329), 13% (5,523) tested positive for antibodies. The positive sample pool included 28.4% (11,468) nurses and 9.3% (3,746) physicians. The results compare to a recent New York State antibody screenings study which revealed 12.3% of the general population had antibodies. Another report from Governor Andrew Cuomo’s office showed 10.5% of the New York Police Department and 17.1% of members of the New York Fire Department and Emergency Medical Technicians tested positive for antibodies. “To help keep our healthcare workers who were on the covid-19 pandemic frontlines, their patients, and loved ones safe and informed, we rolled out free antibody screening across our 23 hospitals,” says Karina W. Davidson, PhD, MASc, professor and senior vice president at the Feinstein Institutes. “As researchers, it’s important to us to share findings from our antibody testing, and we are pleased to know that the personal protective equipment we used was successful in protecting the vast majority of our staff.” The data was analyzed for seroprevalence status, the occurrence of a disease as measured by SARS-CoV-2 IgG presence in a blood sample. Healthcare personnel reported their demographics, work location, and their level of suspicion of virus exposure; 73.7% (29,725) were women, 16% (6,444) were African American, and 14% (5,653) were Hispanic. High levels of HCP-reported suspicion of virus exposure and prior positive diagnostic testing were better indicators of positive results. “Northwell’s Covid-19 Research Consortium and Dr. Davidson are leaders in defining the clinical syndrome and risk factors for SARS-CoV-2,” says Kevin J. Tracey, MD, president and CEO of the Feinstein Institutes. “Patients and healthcare workers alike find these serology results to be reassuring.” For more information, visit the Feinstein Institutes for Medical Research. Featured image: A Northwell Health lab technician conducts antibody serology tests (Courtesy Northwell Health) Reference 1. Moscola J, Sembajwe G, Jarrett M, et al. Prevalence of SARS-CoV-2 antibodies in health care personnel in the New York City area. JAMA. Epub August 06, 2020. doi:10.1001/jama.2020.14765.