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Updated: Jul 15, 2026
A Rapid, Multiplex Dual Reporter IgG and IgM SARS-CoV-2 Neutralization Assay for a Multiplexed Bead-Based Flow Analysis System
Published on: April 6, 2021
The evaluation of a multi-day testing approach with antigen lateral flow devices for people eligible for
Tom Fowler1,2, Alasdair Fellows3, Rachael MacISaac3
1Clinical and Public Health Group, UK Health Security Agency, Nobel House, 17 Smith Square, London, SW1P 3JR, UK.
Background:
COVID-19 therapeutics including antiviral and monoclonal antibody treatments (hereafter 'COVID-19 treatments') require rapid administration to be effective. As part of the community-based antiviral and therapeutic treatment pathway for COVID-19 there has been a move from PCR testing in those eligible to a rapid antigen lateral flow testing regime.
Objectives:
To determine whether a multi-day lateral flow device (LFD) testing regime is a feasible alternative to PCR for diagnosing symptomatic patients eligible for COVID-19 treatments. An LFD regime might return a positive result more quickly than a PCR and hence expedite access to COVID-19 treatments.
Methods:
A retrospective analysis was conducted of diagnostic testing for SARS-CoV-2 with a combination of PCR and LFDs of symptomatic patients eligible for COVID-19 treatments. LFD testing patterns were not assigned. Patients self-censored and the patterns were retro-fitted to the observed results.
Results:
The LFD testing patterns offered high sensitivity, close to 92%; however, the false positive rate also increased, with most of the multi-day testing patterns having a false positive rate greater than 3%. The highest sensitivity was seen among patients who tested with LFD on the same day as PCR.
Conclusions:
There were multiple observed testing behaviours. We conclude that multi-day LFD testing for COVID-19 provides a feasible alternative to PCR to in eligible patients, allowing swift prescription of COVID-19 treatments in most cases. This approach requires acceptance of a trade-off for a small increase in false-positive and -negative results.
