Estimated SARS-CoV-2 antibody seroprevalence trends and relationship to reported case prevalence from a repeated, cross-sectional study in the 50 states and the District of Columbia, United States—October 25, 2020–February 26, 2022

• DOI: 10.1016/j.lana.2022.100403
• Publication Date: 2022-12-02T17:01:48Z
• Authors: Ryan E. Wiegand; Yangyang Deng; Xiaoyi Deng; Adam Lee; William A. Meyer; Stanley Letovsky; Myrna D. Charles; Adi V. Gundlapalli; Adam MacNeil; Aron J. Hall; Natalie J. Thornburg; Jefferson Jones; Ronaldo Iachan; Kristie E.N. Clarke
• Keywords: Seroprevalence; Cross-sectional study; 2019-20 coronavirus outbreak

Sero-surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can reveal trends and differences in subgroups capture undetected or unreported infections that are not included case-based surveillance systems. Cross-sectional, convenience samples remnant sera from clinical laboratories 51 U.S. jurisdictions were assayed for infection-induced SARS-CoV-2 antibodies biweekly October 25, 2020, to July 11, 2021, monthly September 6, February 26, 2022. Test results analyzed infection-induced, nucleocapsid-protein seroprevalence using mixed effects models adjusted demographic variables assay type. Analyses 1,469,792 serum specimens revealed increased 8.0% (95% confidence interval (CI): 7.9%–8.1%) November 2020 58.2% (CI: 57.4%–58.9%) The ratio the change estimated reported case prevalence was 2.8 2.8–2.9) during winter 2020–2021, 2.3 2.0–2.5) summer 3.1 3.0–3.3) 2021–2022. Change ratios ranged 2.6 2.3–2.8) 3.5 3.3–3.7) by region Ratios suggest a high proportion detected periods transmission. largest increases coincided with spread B.1.1.529 (Omicron) variant accessibility home testing. varied season highest midwestern southern United States Our demonstrate counts did fully differing underlying infection rates value sero-surveillance understanding full burden infection. Levels antibody seroprevalence, particularly spikes transmission, important contextualize vaccine effectiveness data as susceptibility population changes. This work supported Centers Disease Control Prevention, Atlanta, Georgia.