Pre-Vaccination Anti-Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Seroprevalence in Workers at Three Japanese Hospitals.

Background: Antibody testing is essential for accurately estimating the number of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to investigate the influence of background factors on seroprevalence by testing for anti-SARS-CoV-2 antibodies in blood samples obtained from the staff of three hospitals.

Methods: This cross-sectional observational study was conducted from June 8 to July 4, 2020, as part of a mandatory health examination.