1. Detection of Nucleocapsid Antibodies Associated with Primary SARS-CoV-2 Infection in Unvaccinated and Vaccinated Blood Donors.
- Author
-
Grebe, Eduard, Grebe, Eduard, Stone, Mars, Spencer, Bryan, Akinseye, Akintunde, Wright, David, Di Germanio, Clara, Bruhn, Roberta, Zurita, Karla, Contestable, Paul, Green, Valerie, Lanteri, Marion, Saa, Paula, Biggerstaff, Brad, Coughlin, Melissa, Kleinman, Steve, Custer, Brian, Jones, Jefferson, Busch, Michael, Grebe, Eduard, Grebe, Eduard, Stone, Mars, Spencer, Bryan, Akinseye, Akintunde, Wright, David, Di Germanio, Clara, Bruhn, Roberta, Zurita, Karla, Contestable, Paul, Green, Valerie, Lanteri, Marion, Saa, Paula, Biggerstaff, Brad, Coughlin, Melissa, Kleinman, Steve, Custer, Brian, Jones, Jefferson, and Busch, Michael
- Abstract
Nucleocapsid antibody assays can be used to estimate SARS-CoV-2 infection prevalence in regions implementing spike-based COVID-19 vaccines. However, poor sensitivity of nucleocapsid antibody assays in detecting infection after vaccination has been reported. We derived a lower cutoff for identifying previous infections in a large blood donor cohort (N = 142,599) by using the Ortho VITROS Anti-SARS-CoV-2 Total-N Antibody assay, improving sensitivity while maintaining specificity >98%. We validated sensitivity in samples donated after self-reported swab-confirmed infections diagnoses. Sensitivity for first infections in unvaccinated donors was 98.1% (95% CI 98.0-98.2) and for infection after vaccination was 95.6% (95% CI 95.6-95.7) based on the standard cutoff. Regression analysis showed sensitivity was reduced in the Delta compared with Omicron period, in older donors, in asymptomatic infections, <30 days after infection, and for infection after vaccination. The standard Ortho N antibody threshold demonstrated good sensitivity, which was modestly improved with the revised cutoff.
- Published
- 2024