Novel bridge multi-species ELISA for detection of SARS-CoV-2 antibodies

• Published in: Journal of immunological methods Vol. 511; p. 113365
• Main Authors: Trabucchi, Aldana, Bombicino, Silvina Sonia, Marfía, Juan Ignacio, Sabljic, Adriana Victoria, Iacono, Rubén Francisco, Smith, Ignacio, Mc callum, Gregorio Juan, Targovnik, Alexandra Marisa, Wolman, Federico Javier, Fingermann, Matías, Alonso, Leonardo Gabriel, Miranda, María Victoria, Valdez, Silvina Noemí
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-12-2022; Published by Elsevier B.V
• Subjects: Animals; Bridge multi-species ELISA; COVID-19 - diagnosis; Dogs; Enzyme-Linked Immunosorbent Assay; Horses; Humans; Immune response; Immunoglobulin G; Rats; SARS-CoV-2; Spike protein; Bridge multi-species ELISA; SARS-CoV-2; Immune response; Spike protein
• ISSN: 0022-1759; 1872-7905
• DOI: 10.1016/j.jim.2022.113365

Considering the course of the current SARS-CoV-2 pandemic, it is important to have serological tests for monitoring humoral immune response against SARS-CoV-2 infection and vaccination. Herein we describe a novel bridge enzyme-linked immunosorbent assay (b-ELISA) for SARS-CoV-2 antibodies detection in human and other species, employing recombinant Spike protein as a unique antigen, which is produced at high scale in insect larvae.
Eighty two human control sera/plasmas and 169 COVID-19 patients' sera/plasmas, confirmed by rRT-PCR, were analyzed by the b-ELISA assay. In addition, a total of 27 animal sera (5 horses, 13 rats, 2 cats and 7 dogs) were employed in order to evaluate the b-ELISA in other animal species.
Out of the 169 patient samples, 129 were positive for IgG anti-SARS-CoV-2 and 40 were negative when they were tested by ELISA COVIDAR® IgG. When a cut-off value of 5.0 SDs was established, 124 out of the 129 COVID-19 positive samples were also positive by our developed b-ELISA (sensitivity: 96.12%). Moreover, the test was able to evaluate the humoral immune response in animal models and also detected as positive a naturally infected cat and two dogs with symptoms, whose owners had suffered the COVID-19 disease.
The obtained results demonstrate that the method developed herein is versatile, as it is able to detect antibodies against SARS-CoV-2 in different animal species without the need to perform and optimize a new assay for each species.