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Oxford University Press - PMC COVID-19 Collection logoLink to Oxford University Press - PMC COVID-19 Collection
. 2022 Feb 7:ciac105. doi: 10.1093/cid/ciac105

Social vulnerability and rurality associated with higher SARS-CoV-2 infection-induced seroprevalence: a nationwide blood donor study, United States, July 2020 – June 2021

Zheng Li 1,, Brian Lewis 2, Kevin Berney 2, Elaine Hallisey 2, Austin M Williams 1, Ari Whiteman 2, Luis O Rivera-González 1, Kristie E N Clarke 1, Heather Clayton 1, Terry Tincher 1, Jean D Opsomer 3, Michael P Busch 4, Adi Gundlapalli 1, Jefferson M Jones 1,
PMCID: PMC8903418  PMID: 35137014

Abstract

Background

Most studies on health disparities during COVID-19 pandemic focused on reported cases and deaths, which are influenced by testing availability and access to care. This study aimed to examine SARS-CoV-2 antibody seroprevalence in the U.S. and its associations with race/ethnicity, rurality, and social vulnerability over time.

Methods

This repeated cross-sectional study used data from blood donations in 50 states and Washington, D.C. from July 2020 through June 2021. Donor ZIP codes were matched to counties and linked with Social Vulnerability Index (SVI) and urban-rural classification. SARS-CoV-2 antibody seroprevalences induced by infection and infection-vaccination combined were estimated. Association of infection-induced seropositivity with demographics, rurality, SVI, and its four themes were quantified using multivariate regression models.

Findings

Weighted seroprevalence differed significantly by race/ethnicity and rurality, and increased with increasing social vulnerability. During the study period, infection-induced seroprevalence increased from 1.6% to 27.2% and 3.7% to 20.0% in rural and urban counties, respectively, while rural counties had lower combined infection- and vaccination-induced seroprevalence (80.0% vs. 88.1%) in June 2021. Infection-induced seropositivity was associated with being Hispanic, non-Hispanic Black, and living in rural or higher socially vulnerable counties, after adjusting for demographic and geographic covariates.

Conclusion

The findings demonstrated increasing SARS-CoV-2 seroprevalence in the U.S. across all geographic, demographic, and social sectors. The study illustrated disparities by race-ethnicity, rurality, and social vulnerability. The findings identified areas for targeted vaccination strategies and can inform efforts to reduce inequities and prepare for future outbreaks.

Keywords: SARS-CoV-2, COVID-19, serological survey, seroprevalence, rural, social vulnerability, health equity

Supplementary Material

ciac105_suppl_Supplementary_Material

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

ciac105_suppl_Supplementary_Material

Articles from Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America are provided here courtesy of Oxford University Press

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