Antibody testing for COVID-19: A report from the National COVID Scientific Advisory Panel


Emily R. Adams1, Mark Ainsworth2, Rekha Anand3, Monique I. Andersson 2, Kathryn Auckland4, J. Kenneth Baillie5, Eleanor Barnes2,4, Sally Beer 2, John I. Bell4, Tamsin Berry6, Sagida Bibi7, Miles Carroll4,8, Senthil K. Chinnakannan 4, Elizabeth Clutterbuck7, Richard J. Cornall 2,4, Derrick W. Crook 2,4, Thushan de Silva9, Wanwisa Dejnirattisai4, Kate E. Dingle 4, Christina Dold7, Alexis Espinosa2, David W. Eyre2,4, Helen Farmer6, Maria Fernandez Mendoza2, Dominique Georgiou2, Sarah J. Hoosdally4, Alastair Hunter10, Katie Jefferey 2, Dominic F. Kelly2,7, Paul Klenerman2,4, Julian Knight2,4, Clarice Knowles6, Andrew J. Kwok4, Ullrich Leuschner11, Robert Levin12, Chang Liu4, César López-Camacho 4, Jose Martinez2, Philippa C. Matthews 2,4, Hannah McGivern 13, Alexander J. Mentzer 2,4, Jonathan Milton13, Juthathip Mongkolsapaya4, Shona C. Moore14, Marta S. Oliveira13, Fiona Pereira15, Elena Perez2, Timothy Peto2,4, Rutger J. Ploeg 2,13, Andrew Pollard 2,7, Tessa Prince 14, David J. Roberts11, Justine K. Rudkin 4, Veronica Sanchez2, Gavin R. Screaton4, Wellcome Open Research 2020, 5:139 Last updated: 18 MAY 2021 Malcolm G. Semple 14,16, Jose Slon-Campos4, Donal T. Skelly 2,17, Elliot Nathan Smith6, Alberto Sobrinodiaz2, Julie Staves2, David I. Stuart 4,18, Piyada Supasa4, Tomas Surik13, Hannah Thraves2, Pat Tsang11, Lance Turtle A. Sarah Walker4, Beibei Wang4, Charlotte Washington3, Nicholas Watkins20, James Whitehouse6, National COVID Testing Scientific Advisory Panel


Background: The COVID-19 pandemic caused >1 million infections during January-March 2020. There is an urgent need for reliable antibody detection approaches to support diagnosis, vaccine development, safe release of individuals from quarantine, and population lock-down exit strategies. We set out to evaluate the performance of ELISA and lateral flow immunoassay (LFIA) devices.Methods: We tested plasma for COVID (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2) IgM and IgG antibodies by ELISA and using nine different LFIA devices. We used a panel of plasma samples from individuals who have had confirmed COVID infection based on a PCR result (n=40), and pre-pandemic negative control samples banked in the UK prior to December-2019 (n=142).Results: ELISA detected IgM or IgG in 34/40 individuals with a confirmed history of COVID infection (sensitivity 85%, 95%CI 70-94%), vs. 0/50 pre-pandemic controls (specificity 100% [95%CI 93-100%]). IgG levels were detected in 31/31 COVID-positive individuals tested ≥10 days after symptom onset (sensitivity 100%, 95%CI 89-100%). IgG titres rose during the 3 weeks post symptom onset and began to fall by 8 weeks, but remained above the detection threshold. Point estimates for the sensitivity of LFIA devices ranged from 55-70% versus RT-PCR and 65-85% versus ELISA, with specificity 95-100% and 93-100% respectively. Within the limits of the study size, the performance of most LFIA devices was similar.Conclusions: Currently available commercial LFIA devices do not perform sufficiently well for individual patient applications. However, ELISA can be calibrated to be specific for detecting and quantifying SARS-CoV-2 IgM and IgG and is highly sensitive for IgG from 10 days following first symptoms.


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Research Themes:

2. Diagnostic and Host Response