Serological response in health care workers after a single dose of SARS-CoV-2 vaccine using six automated SARS-CoV-2 antibody assays

•The S-specific assays from Roche, Siemens, DiaSorin, and Abbott detected and quantified anti-S antibodies postvaccination and/or infection.•Clinicians should be aware of the phenomenon of assay-specific antibody waning when using the combination of N- and S-specific serological assays to differentiate individuals with postinfection or vaccination immunization.•Median anti-S levels for all four assays were significantly higher (P< 0.001) after a single vaccination in persons with a previous infection compared to those without a previous infection. Spike (S)- and nucleocapsid (N)-specific serological assay responses were determined before and/or after first dose SARS-CoV-2 vaccination in 22 individuals. S-specific assays quantified antibodies after vaccination with significant higher levels in participants with a previous infection. Be cautious combining N-/S-specific assay results, potentially differentiating post-infection/vaccination immunization as assay-specific N-antibody waning was observed.