Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
[Preprint]. 2023 Feb 10:2023.02.09.23285583.
doi: 10.1101/2023.02.09.23285583.

Sensitivity of Rapid Antigen Tests Against SARS-CoV-2 Omicron and Delta Variants

Anuradha Rao  1   2 , Adrianna Westbrook  1   2 , Leda Bassit  1   3 , Richard Parsons  1   4 , Eric Fitts  5 , Morgan Greenleaf  1   6 , Kaleb McLendon  1   5   7 , Julie A Sullivan  1   2 , William O'Sick  1   5   7 , Tyler Baugh  1   5   7 , Heather B Bowers  1   3 , Filipp Frank  8 , Ethan Wang  9 , Mimi Le  2 , Jennifer Frediani  1   4 , Pavitra Roychoudhury  10 , Alexander L Greninger  10 , Robert Jerris  11 , Nira R Pollock  12 , Eric A Ortlund  1   8 , John D Roback  1   5   7 , Wilbur A Lam  1   2   13   14 , Anne Piantadosi  5   9
Affiliations

Sensitivity of Rapid Antigen Tests Against SARS-CoV-2 Omicron and Delta Variants

Anuradha Rao et al. medRxiv. .

Update in

  • Sensitivity of rapid antigen tests against SARS-CoV-2 Omicron and Delta variants.
    Rao A, Westbrook A, Bassit L, Parsons R, Fitts E, Greenleaf M, McLendon K, Sullivan JA, O'Sick W, Baugh T, Bowers HB, Frank F, Wang E, Le M, Frediani J, Roychoudhury P, Greninger AL, Jerris R, Pollock NR, Ortlund EA, Roback JD, Lam WA, Piantadosi A. Rao A, et al. J Clin Microbiol. 2023 Oct 24;61(10):e0013823. doi: 10.1128/jcm.00138-23. Epub 2023 Sep 20. J Clin Microbiol. 2023. PMID: 37728336 Free PMC article.

Abstract

Rapid Antigen Tests (RAT) have become an invaluable tool for combating the COVID-19 pandemic. However, concerns have been raised regarding the ability of existing RATs to effectively detect emerging SARS-CoV-2 variants. We compared the performance of eight commercially available, emergency use authorized RATs against the Delta and Omicron SARS-CoV-2 variants using individual patient and serially diluted pooled clinical samples. The RATs exhibited lower sensitivity for Omicron samples when using PCR Cycle threshold (C T ) value (a proxy for RNA concentration) as the comparator. Interestingly, however, they exhibited similar sensitivity for Omicron and Delta samples when using quantitative antigen concentration as the comparator. We further found that the Omicron samples had lower ratios of antigen to RNA, which offers a potential explanation for the apparent lower sensitivity of RATs for that variant when using C T value as a reference. Our findings underscore the complexity in assessing RAT performance against emerging variants and highlight the need for ongoing evaluation in the face of changing population immunity and virus evolution.

PubMed Disclaimer

Conflict of interest statement

Conflict-of-interest statement

ALG reports contract testing from Abbott, Cepheid, Novavax, Pfizer, Janssen, and Hologic, and research support from Gilead and Merck, outside of the described work.

The other authors have declared that no conflict of interest exists.

Figures

Fig. 1.
Fig. 1.. Results of testing 8 commercially available rapid antigen tests against remnant clinical sample pools.
Each of eight commercially available rapid antigen tests (RATs) was tested using sequence-confirmed, serially diluted and quantified (N2 CT CDC Assay and Quanterix Simoa SARS-CoV-2 N Protein Antigen Test) pools generated from remnant clinical samples (RCS) of the same variant. Panels A and B show each RAT’s limit of detection, which is the lowest antigen concentration (A) or highest CT value (B) that was detected in five out of five replicates. When testing was repeated with independent RCS pools, or independent lots of tests, they are presented as separate data points.
Fig. 2.
Fig. 2.. Results of testing 2 commercially available rapid antigen tests against individual remnant clinical samples for Delta (A and B) and Omicron (C and D).
Sequence-verified residual mid turbinate samples from 75 individuals with Delta infection and 84 individuals with BA.1 infection underwent RT-PCR testing using the Xpert Xpress CoV-2/Flu/RSV plus & Xpert Xpress SARS-CoV-2 assays (Cepheid), protein quantification using the Simoa SARS-CoV-2 N Protein Antigen assay (Quanterix), and rapid antigen testing (QuickVue or Binax) according to the manufacturer’s instructions. Y-axes reflect natural log(n+1) transformed antigen concentration. Abbreviations: Cycle threshold (CT)
Fig. 3.
Fig. 3.. Correlation between antigen concentration and CT value for individual remnant clinical samples.
Sequence-verified residual mid turbinate samples from 163 individuals with Delta infection and 169 individuals with BA.1 infection underwent RT-PCR testing using the Xpert Xpress CoV-2/Flu/RSV plus & Xpert Xpress SARS-CoV-2 assays (Cepheid) and protein testing using the Simoa SARS-CoV-2 N Protein Antigen assay (Quanterix), according to the manufacturer’s instructions. Y-axes reflect natural log(n+1) transformed antigen concentration. The red circle signifies 41 Delta samples whose CT values were above the assay detection limit and antigen concentrations were below the assay detection limit. Abbreviations: Cycle threshold (CT).
See this image and copyright information in PMC

References

    1. https://www.fda.gov/medical-devices/coronavirus-disease-2019-covid-19-em.... 2019. [
    1. Osterman A, Badell I, Basara E, Stern M, Kriesel F, Eletreby M, et al. Impaired detection of omicron by SARS-CoV-2 rapid antigen tests. Med Microbiol Immunol. 2022;211(2-3):105–17. - PMC - PubMed
    1. Schrom J, Marquez C, Pilarowski G, Wang CY, Mitchell A, Puccinelli R, et al. Comparison of SARS-CoV-2 Reverse Transcriptase Polymerase Chain Reaction and BinaxNOW Rapid Antigen Tests at a Community Site During an Omicron Surge : A Cross-Sectional Study. Ann Intern Med. 2022;175(5):682–90. - PMC - PubMed
    1. Bayart JL, Degosserie J, Favresse J, Gillot C, Didembourg M, Djokoto HP, et al. Analytical Sensitivity of Six SARS-CoV-2 Rapid Antigen Tests for Omicron versus Delta Variant. Viruses. 2022;14(4). - PMC - PubMed
    1. Bekliz M, Adea K, Puhach O, Perez-Rodriguez F, Marques Melancia S, Baggio S, et al. Analytical Sensitivity of Eight Different SARS-CoV-2 Antigen-Detecting Rapid Tests for Omicron-BA.1 Variant. Microbiol Spectr. 2022;10(4):e0085322. - PMC - PubMed

Publication types