Development and validation of an enzyme-linked immunoassay kit for diagnosis and surveillance of COVID-19

Flávia F Bagno; Sarah A R Sérgio; Maria Marta Figueiredo; Lara C Godoi; Luis A F Andrade; Natália C Salazar; Camila P Soares; Andressa Aguiar; Flávia Jaqueline Almeida; Edimilson D da Silva; Antônio G P Ferreira; Edison Luiz Durigon; Ricardo T Gazzinelli; Santuza M R Teixeira; Ana Paula S M Fernandes; Flavio G da Fonseca

doi:10.1016/j.jcvp.2022.100101

Development and validation of an enzyme-linked immunoassay kit for diagnosis and surveillance of COVID-19

J Clin Virol Plus. 2022 Aug;2(3):100101. doi: 10.1016/j.jcvp.2022.100101. Epub 2022 Aug 6.

Authors

Flávia F Bagno^{1

2}, Sarah A R Sérgio¹, Maria Marta Figueiredo^{1

3}, Lara C Godoi¹, Luis A F Andrade¹, Natália C Salazar¹, Camila P Soares⁴, Andressa Aguiar⁵, Flávia Jaqueline Almeida⁶, Edimilson D da Silva², Antônio G P Ferreira², Edison Luiz Durigon⁴, Ricardo T Gazzinelli^{1

7}, Santuza M R Teixeira^{1

8}, Ana Paula S M Fernandes^{1

9}, Flavio G da Fonseca^{1

10}

Affiliations

¹ Centro de Tecnologia de Vacinas (CT Vacinas), BH-Tec, UFMG. Belo Horizonte, MG, Brazil.
² Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
³ Universidade Estadual de Minas Gerais, Divinópolis, MG, Brazil.
⁴ Universidade de São Paulo (USP), Instituto de Ciências Biomédicas, São Paulo, SP, Brazil.
⁵ Geriatric and Convalescent Hospital Dom Pedro II, São Paulo, SP, Brazil.
⁶ Department of Pediatrics, Santa Casa de São Paulo School of Medical Sciences, São Paulo, SP, Brazil.
⁷ Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas René Rachou, Belo Horizonte, MG, Brazil.
⁸ Universidade Federal de Minas Gerais, Depto de Bioquímica e Imunologia, Belo Horizonte, MG, Brazil.
⁹ Universidade Federal de Minas Gerais, Faculdade de Farmácia, Belo Horizonte, MG, Brazil.
¹⁰ Universidade Federal de Minas Gerais, Depto de Microbiologia, ICB/UFMG, Belo Horizonte, MG, Brazil.

Abstract

There is a massive demand to identify alternative methods to detect new cases of COVID-19 as well as to investigate the epidemiology of the disease. In many countries, importation of commercial kits poses a significant impact on their testing capacity and increases the costs for the public health system. We have developed an ELISA to detect IgG antibodies against SARS-CoV-2 using a recombinant viral nucleocapsid (rN) protein expressed in E. coli. Using a total of 894 clinical samples we showed that the rN-ELISA was able to detect IgG antibodies against SARS-CoV-2 with high sensitivity (97.5%) and specificity (96.3%) when compared to a commercial antibody test. After three external validation studies, we showed that the test accuracy was higher than 90%. The rN-ELISA IgG kit constitutes a convenient and specific method for the large-scale determination of SARS-CoV-2 antibodies in human sera with high reliability.

Keywords: COVID-19; Diagnosis; ELISA; Prototyping; SARS-CoV-2; Serological assay.