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Volume 30, Number 8—August 2024
Research

Detection of Nucleocapsid Antibodies Associated with Primary SARS-CoV-2 Infection in Unvaccinated and Vaccinated Blood Donors

Eduard Grebe1Comments to Author , Mars Stone1, Bryan R. Spencer, Akintunde Akinseye, David J. Wright, Clara Di Germanio, Roberta Bruhn, Karla G. Zurita, Paul Contestable, Valerie Green, Marion C. Lanteri, Paula Saa, Brad J. Biggerstaff, Melissa M. Coughlin, Steve Kleinman, Brian Custer, Jefferson M. Jones, and Michael P. Busch
Author affiliations: Vitalant Research Institute, San Francisco, California, USA (E. Grebe, M. Stone, C. Di Germanio, R. Bruhn, K.G. Zurita, B. Custer, M.P. Busch); University of California, San Francisco (M. Stone, R. Bruhn, M.C. Lanteri, B. Custer, M.P. Busch); American Red Cross, Rockville, Maryland, USA (B.R. Spencer, P. Saa); Westat, Rockville (A. Akinseye, D. Wright); QuidelOrtho, Rochester, New York, USA (P. Contestable); Creative Testing Solutions, Tempe, Arizona, USA (V. Green, M.C. Lanteri); Centers for Disease Control and Prevention, Fort Collins, Colorado, USA (B.J. Biggerstaff); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (M.M. Coughlin, J.M. Jones); University of British Columbia, Vancouver, British Columbia, Canada (S. Kleinman)

Main Article

Table

Sensitivity of SARS-CoV-2 nucleocapsid antibody assay for detection of first infections in unvaccinated and vaccinated donors, United States, July 2021–December 2022*

Characteristic Sensitivity for detection of first infections in unvaccinated donors
 Sensitivity for detection of first infections in vaccinated donors
No. donors Manufacturer’s cutoff,† % (95% CI) Revised cutoff,‡
% (95% CI)		 No. donors Manufacturer’s cutoff,† % (95% CI) Revised cutoff,‡ % (95% CI)
Overall 2,751 98.1 (98.0–98.2) 98.4 (98.4–98.5) 8,187 95.6 (95.6–95.7) 97.0 (96.9–97.0)
Delta: Jul–Dec 2021 1,343 98.4 (98.2–98.5) 98.5 (98.4–98.6) 1,349 93.9 (93.5–94.4) 95.3 (94.9–95.6)
Omicron: Jan–Dec 2022 1,408 97.9 (97.7–98.0) 98.4 (98.3–98.5) 6,838 96.0 (95.9–96.0) 97.3 (97.3–97.4)
Age <65 y 2,225 98.2 (98.1–98.2) 98.4 (98.4–98.5) 5,194 96.2 (96.1–96.3) 97.3 (97.2–97.3)
Age >65 y 526 97.9 (97.5–98.3) 98.5 (98.2–98.8) 2,993 94.7 (94.5–94.9) 96.5 (96.4–96.6)
Symptomatic§ 2,430 98.4 (98.3–98.4) 98.7 (98.7–98.8) 7,416 96.2 (96.1–96.2) 97.5 (97.5–97.6)
Asymptomatic§ 208 96.6 (95.0–98.3) 96.6 (95.0–98.3) 627 90.1 (88.5–91.7) 91.2 (89.8–92.6)

*Proportion reactive in the first sample collected after reported swab-confirmed infection, collected 14 to 180 days postinfection. †Signal-to-cutoff ratio >1.000. ‡Signal-to-cutoff ratio >0.395. §Symptomatic or asymptomatic status could not be ascertained for all infections because of incomplete survey responses.

Main Article

1These first authors contributed equally to this article.

Page created: June 10, 2024
Page updated: July 23, 2024
Page reviewed: July 23, 2024
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