Two serological approaches for detection of antibodies to SARS-CoV-2 in different scenarios: a screening tool and a point-of-care test
Alexis C.R. Hoste, Angel Venteo, Alba Fresco-Taboada, Istar Tapia, Alejandro Monedero, Lissette López, Maarten F. Jebbink, Elisa Pérez-Ramírez, Miguel Angel Jimenez-Clavero, Mercedes Almonacid, Patricia Muñoz, Jesus Guinea, Carmen Vela, Lia van der Hoek, Paloma Rueda, Patricia Sastre.
Detecting antibodies against SARS-CoV-2 is an indicator of previous exposure to the virus. Therefore Ingenasa developed two assays, both based on “double recognition”: an enzyme-linked immunosorbent assay (DR-ELISA) and a lateral flow assay (DR-LFA). A double recognition assay is based on the use of the same protein as the target antigen and detection molecule, using the principle that antibodies possess multiple antigen binding regions (2 for IgG, 4 for IgA, and 10 for IgM), that can bind both: the target and detection antigen. The SARS-CoV-2 DR tests were based on the Nucleocapsid protein of the virus, and evaluated with > 1000 SARS-CoV-2 antibody positive and negative samples. A high sensitivity and specificity was found: between 91.2% and 100%, and specificity of 100% and 98.2% for DR-LFA and DR-ELISA, respectively. Besides being specific and sensitive, the tests also offer the unique advantage that serum samples from animal species can be tested since the assays use the target antigen as the detector.
Published December 2020 in Diagnostic Microbiology and Infectious Disease