{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T03:45:44Z","timestamp":1775187944881,"version":"3.50.1"},"reference-count":28,"publisher":"Oxford University Press (OUP)","issue":"12","funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000054","name":"National Cancer Institute","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000054","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["HHSN261200800001E"],"award-info":[{"award-number":["HHSN261200800001E"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2021,12,15]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>False positivity may hinder the utility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests in sub-Saharan Africa.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>From 312 Malian samples collected before 2020, we measured antibodies to the commonly tested SARS-CoV-2 antigens and 4 other betacoronaviruses by enzyme-linked immunosorbent assay (ELISA). In a subset of samples, we assessed antibodies to a panel of Plasmodium falciparum antigens by suspension bead array and functional antiviral activity by SARS-CoV-2 pseudovirus neutralization assay. We then evaluated the performance of an ELISA using SARS-CoV-2 spike protein and receptor-binding domain developed in the United States using Malian positive and negative control samples. To optimize test performance, we compared single- and 2-antigen approaches using existing assay cutoffs and population-specific cutoffs.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Background reactivity to SARS-CoV-2 antigens was common in prepandemic Malian samples. The SARS-CoV-2 reactivity varied between communities, increased with age, and correlated negligibly\/weakly with other betacoronavirus and P falciparum antibodies. No prepandemic samples demonstrated functional activity. Regardless of the cutoffs applied, test specificity improved using a 2-antigen approach. Test performance was optimal using a 2-antigen assay with population-specific cutoffs (sensitivity, 73.9% [95% confidence interval {CI}, 51.6\u201389.8]; specificity, 99.4% [95% CI, 97.7\u201399.9]).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>We have addressed the problem of SARS-CoV-2 seroassay performance in Africa by using a 2-antigen assay with cutoffs defined by performance in the target population.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/infdis\/jiab498","type":"journal-article","created":{"date-parts":[[2021,10,5]],"date-time":"2021-10-05T17:27:40Z","timestamp":1633454860000},"page":"2001-2009","source":"Crossref","is-referenced-by-count":21,"title":["Severe Acute Respiratory Syndrome Coronavirus 2 Seroassay Performance and Optimization in a Population With High Background Reactivity in Mali"],"prefix":"10.1093","volume":"224","author":[{"given":"John","family":"Woodford","sequence":"first","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Issaka","family":"Sagara","sequence":"additional","affiliation":[{"name":"Malaria Research and Training Center\/University of Science, Techniques, and Technologies of Bamako, Bamako, Mali"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alassane","family":"Dicko","sequence":"additional","affiliation":[{"name":"Malaria Research and Training Center\/University of Science, Techniques, and Technologies of Bamako, Bamako, Mali"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amatigue","family":"Zeguime","sequence":"additional","affiliation":[{"name":"Malaria Research and Training Center\/University of Science, Techniques, and Technologies of Bamako, Bamako, Mali"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M\u2019Bouye","family":"Doucoure","sequence":"additional","affiliation":[{"name":"Malaria Research and Training Center\/University of Science, Techniques, and Technologies of Bamako, Bamako, Mali"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jennifer","family":"Kwan","sequence":"additional","affiliation":[{"name":"Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Irfan","family":"Zaidi","sequence":"additional","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Justin","family":"Doritchamou","sequence":"additional","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maryonne","family":"Snow-Smith","sequence":"additional","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nada","family":"Alani","sequence":"additional","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jonathan","family":"Renn","sequence":"additional","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ivan","family":"Kosik","sequence":"additional","affiliation":[{"name":"Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jaroslav","family":"Holly","sequence":"additional","affiliation":[{"name":"Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jonathan","family":"Yewdell","sequence":"additional","affiliation":[{"name":"Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dominic","family":"Esposito","sequence":"additional","affiliation":[{"name":"Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2587-8330","authenticated-orcid":false,"given":"Kaitlyn","family":"Sadtler","sequence":"additional","affiliation":[{"name":"National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4483-5005","authenticated-orcid":false,"given":"Patrick","family":"Duffy","sequence":"additional","affiliation":[{"name":"Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2021,10,6]]},"reference":[{"key":"2021121513493620000_CIT0001","doi-asserted-by":"crossref","first-page":"eabc6347","DOI":"10.1126\/sciimmunol.abc6347","article-title":"Serology for SARS-CoV-2: apprehensions, opportunities, and the path forward.","volume":"5","author":"Bryant","year":"2020","journal-title":"Sci Immunol"},{"key":"2021121513493620000_CIT0002","doi-asserted-by":"crossref","first-page":"e02148","DOI":"10.1128\/JCM.02148-20","article-title":"Application, verification, and implementation of 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