SARS-CoV-2 rapid antigen test: High sensitivity to detect infectious virus

J Clin Virol. 2021 Jul:140:104846. doi: 10.1016/j.jcv.2021.104846. Epub 2021 Apr 24.

Abstract

Background: The COVID-19 pandemic has highlighted the need for rapid, cost effective and easy-to-use diagnostic tools for SARS-CoV-2 infections that can be used in point of care settings to limit disease transmission.

Objective: We evaluated two rapid antigen immunochromatographic tests, Abbott Panbio™ COVID-19 Ag Rapid Test (Panbio) and Zhejiang Orient Gene/Healgen Biotech Coronavirus Ag rapid test cassette (Orient gene) for detection of infectious SARS-CoV-2.

Results: The tests were evaluated on nasopharyngeal samples taken from individuals having respiratory and/or COVID-19 related symptoms, which had been analyzed for SARS-CoV-2 RNA using real-time PCR. In total 156 PCR-positive, and 130 (Panbio) and 176 (Orient Gene) PCR-negative samples were analyzed. Overall sensitivity and specificity were 71.8% and 100% for Panbio and 79.5% and 74.4% for the Orient Gene test respectively. The false positives by the Orient Gene test were verified as SARS-CoV-2 negative by in-house real-time PCR assay and were negative for the four seasonal coronaviruses. Subgroup analysis revealed that the antigen tests had high sensitivity for samples with Ct-values <25 (>88%) and for samples containing infectious viruses as determined by cultivation on Vero cells, 94.1% and 97.1% for the Panbio and Orient gene tests, respectively. Furthermore, both tests had a sensitivity of <50 picogram for nucleocapsid protein. No sample with a Ct-value >27 was shown to contain infectious virus.

Conclusion: The results indicate that the rapid antigen tests, especially the Panbio tests may be a valuable tool to detect contagious persons during the ongoing pandemic.

Keywords: Infectious virus; Rapid antigen test; SARS-CoV-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Viral / analysis*
  • COVID-19 Testing
  • COVID-19* / diagnosis
  • Chlorocebus aethiops
  • Humans
  • Pandemics
  • RNA, Viral
  • SARS-CoV-2* / isolation & purification
  • Sensitivity and Specificity
  • Vero Cells

Substances

  • Antigens, Viral
  • RNA, Viral