Research led from Oxford has found that an immunological assay commonly used to measure antibodies, antigens and proteins in biological samples can be specifically adapted to detect and quantifying COVID-19 antibodies.
The investigations by the National COVID Testing Scientific Advisory Panel were co-ordinated by Prof Derrick Crook at the University of Oxford. The trial involved researchers at Oxford University Hospitals NHS Foundation Trust, NHS Blood and Transplant, and ISARIC CCP-UK, University of Liverpool. Funding was provided by the NIHR Oxford Biomedical Research Centre (BRC), Wellcome Trust, MRC and the Department of Health and Social Care
They found that an enzyme-linked immunosorbent assay (ELISA) could be calibrated to be specific for detecting and quantifying SARS-CoV-2 (COVID-19) IgM and IgG immunoglobulin, and was highly sensitive for IgG immunoglobulin from 10 days following the onset of symptoms.
The study, published as a pre-print on medRxiv, also found that the performance of current lateral flow immunoassay (LFIA) devices was inadequate for most individual patient applications.
Prof Crook said: “There is an urgent need for robust and reliable antibody detection approaches to support diagnostics, the development of vaccines and the ability of people to leave quarantine safely.
“There has been considerable interest in LFIA devices – which work like pregnancy tests – but our study has found that these kits are not sensitive or specific enough, and their overall performance makes them unsuitable for testing individuals.”
The research team used a panel of plasma samples designated SARS-CoV-2 positive and negative and tested them for SARS-Cov-2 IgM and IgG antibodies using ELISA and nine different commercially available LFIA devices.
Gavin Screaton, Head of the University of Oxford’s Medical Sciences Division, said: “This has been a fantastic collaborative effort by a large national consortium of researchers.
“The novel in-house ELISA test has performed very well in these trials, and provides a clear way forward for the development of commercial high-throughput antibody testing.