Shalaby, A., Laharwani, H., Bates, J.T., Kyle, P.B. Efficacy of POC Antibody Assays after COVID-19 Infection and Potential Utility for "Immunity Passports". Lab Med. 2021 Nov 14:lmab093. doi: 10.1093/labmed/lmab093. Epub ahead of print. PMID: 34791323; PMCID: PMC8690030.
Numerous manufacturers market lateral flow assays for the detection of SARS-CoV-2 antibodies, but there are many questions about the reliability and efficacy of these tests. Serum specimens from 60 individuals were analyzed using 2 lateral flow antibody assays, an in-house enzyme-linked immunosorbent assay (ELISA), and the Abbott SARS-CoV-2 IgG chemiluminescent immunoassay. The BioMedomics and Premier Biotech lateral flow assays were positive for IgM in 73.3% and 70% and for IgG in 80% and 73.3% of specimens, respectively. The ELISA assay was positive for IgM and IgG in 73.3% and 86.7% of specimens from infected individuals, whereas the Abbott assay was positive in 80%. The specificities of the 4 assays ranged from 96.7% to 100% for IgM and from 93.3% to 100% for IgG. Results of the 2 lateral flow assays were comparable to those of the ELISA and Abbott assays. Assay efficacy depended on length of time after SARS-CoV-2 infection.