Evaluation of antibody testing for SARS-Cov-2 using ELISA and lateral flow immunoassays

Emily R Adams; Rekha Anand; Monique I Andersson; Kathryn Auckland; J Kenneth Baillie; Eleanor Barnes; John Bell; Tamsin Berry; Sagida Bibi; Miles Carroll; Senthil Chinnakannan; Elizabeth Clutterbuck; Richard J Cornall; Derrick W Crook; Thushan De Silva; Wanwisa Dejnirattisai; Kate E Dingle; Christina Dold; David W Eyre; Helen Farmer; Sarah J Hoosdally; Alistair Hunter; Katie Jeffrey; Paul Klenerman; Julian Knight; Clarice Knowles; Andrew J Kwok; Ullrich Leuschner; Chang Liu; Cesar Lopez-Camacho; Philippa C Matthews; Hannah McGivern; Alexander J Mentzer; Jonathan Milton; Juthathip Mongkolsapaya; Shona C Moore; Marta S Oliveira; Fiona Pereira; Timothy Peto; Rutger J Ploeg; Andrew Pollard; Tessa Prince; David J Roberts; Justine K Rudkin; Gavin R Screaton; Malcolm G Semple; Donal T Skelly; Elliot Nathan Smith; Julie Staves; David Stuart; Piyada Supasa; Tomas Surik; Pat Tsang; Lance Turtle; A Sarah Walker; Beibei Wang; Charlotte Washington; Nicholas Watkins; James Whitehouse; Sally Beer; Robert Levin; Alexis Espinosa; Dominique Georgiou; Jose Carlos Martinez Garrido; Hannah Thraves; Elena Perez Lopez; Maria del Rocio Fernandez Mendoza; Alberto Jose Sobrino Diaz; Veronica Sanchez

We first considered performance of the nine different LFIA devices using RT-PCR-confirmed cases as the reference standard (Table 1A, Figure S1 ) and considering any LFIA positive result (IgM, IgG or both) as positive. The LFIA devices achieved sensitivity ranging from 55% (95%CI 36-72%) to 70% (51-84%) and specificity from 95% (95%CI 86-99%) to 100% (94-100%). There was no evidence of differences between the devices in sensitivity (p≥0.015, cf. Benjamini-Hochberg p=0.0014 threshold) or specificity (p≥0.19 for all devices with at least one falsepositive test). Restricting to 31 samples collected ≥10 days post symptom-onset (all ELISA IgGpositive), LFIA sensitivity ranged from 61% (95%CI 39-80%) to 88% (68-97%) ( Table S4) .