Fig. 3From: Genetic testing and serological screening for SARS-CoV-2 infection in a COVID-19 outbreak in a nursing facility in JapanClinical course of residents with PCR-negative and IgG-positive results for SARS-CoV-2. The serum sample obtained from resident no. 28 on May 1 was the one remaining from biochemical testing. The calculated signal-to-cutoff values of ≥1.4 indicate positive detection of anti-SARS-CoV-2 IgG antibodies. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2Back to article page