TY  - JOUR
A1  - Emmerich, Petra
A1  - Murawski, Carolin
A1  - Ehmen, Christa
A1  - von Possel, Ronald
A1  - Pekarek, Neele
A1  - Oestereich, Lisa
A1  - Duraffour, Sophie
A1  - Pahlmann, Meike
A1  - Struck, Nicole
A1  - Eibach, Daniel
A1  - Krumkamp, Ralf
A1  - Amuasi, John
A1  - Maiga‐Ascofaré, Oumou
A1  - Rakotozandrindrainy, Raphael
A1  - Asogun, Danny
A1  - Ighodalo, Yemisi
A1  - Kann, Simone
A1  - May, Jürgen
A1  - Tannich, Egbert
A1  - Deschermeier, Christina
T1  - Limited specificity of commercially available SARS‐CoV‐2 IgG ELISAs in serum samples of African origin
JF  - Tropical Medicine & International Health
N2  - Objectives
Specific serological tests are mandatory for reliable SARS‐CoV‐2 diagnostics and seroprevalence studies. Here, we assess the specificities of four commercially available SARS‐CoV‐2 IgG ELISAs in serum/plasma panels originating from Africa, South America, and Europe.

Methods
882 serum/plasma samples collected from symptom‐free donors before the COVID‐19 pandemic in three African countries (Ghana, Madagascar, Nigeria), Colombia, and Germany were analysed with three nucleocapsid‐based ELISAs (Euroimmun Anti‐SARS‐CoV‐2‐NCP IgG, EDI™ Novel Coronavirus COVID‐19 IgG, Mikrogen recomWell SARS‐CoV‐2 IgG), one spike/S1‐based ELISA (Euroimmun Anti‐SARS‐CoV‐2 IgG), and in‐house common cold CoV ELISAs.

Results
High specificity was confirmed for all SARS‐CoV‐2 IgG ELISAs for Madagascan (93.4–99.4%), Colombian (97.8–100.0%), and German (95.9–100.0%) samples. In contrast, specificity was much lower for the Ghanaian and Nigerian serum panels (Ghana: NCP‐based assays 77.7–89.7%, spike/S1‐based assay 94.3%; Nigeria: NCP‐based assays 39.3–82.7%, spike/S1‐based assay 90.7%). 15 of 600 African sera were concordantly classified as positive in both the NCP‐based and the spike/S1‐based Euroimmun ELISA, but did not inhibit spike/ACE2 binding in a surrogate virus neutralisation test. IgG antibodies elicited by previous infections with common cold CoVs were found in all sample panels, including those from Madagascar, Colombia, and Germany and thus do not inevitably hamper assay specificity. Nevertheless, high levels of IgG antibodies interacting with OC43 NCP were found in all 15 SARS‐CoV‐2 NCP/spike/S1 ELISA positive sera.

Conclusions
Depending on the chosen antigen and assay protocol, SARS‐CoV‐2 IgG ELISA specificity may be significantly reduced in certain populations probably due to interference of immune responses to endemic pathogens like other viruses or parasites.
KW  - SARS‐CoV‐2
KW  - seroepidemiologic studies
KW  - immunoglobulin G
KW  - Enzyme‐Linked Immunosorbent Assay
KW  - specificity
KW  - Africa
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239899
VL  - 26
IS  - 6
SP  - 621
EP  - 631
ER  -