Comparison of the Performance of the PanBio COVID-19 Antigen Test in SARS-CoV-2 B.1.1.7 (Alpha) Variants versus non-B.1.1.7 Variants

ABSTRACT This study evaluates the performance of the PanBio COVID-19 antigen (Ag) test as part of a hospital infection control policy. Hospital staff was encouraged to get tested for COVID-19 when presenting with SARS-CoV-2-related symptoms. In a period of approximately 5 months, a steady decline in the performance of the Ag test was noted, epidemiologically coinciding with the rise of the SARS-CoV-2 B.1.1.7 (alpha) variant of concern (VOC) in the Netherlands. This led to the hypothesis that the diagnostic performance of the PanBio COVID-19 Ag test was influenced by the infecting viral variant. The results show a significantly lower sensitivity of the PanBio COVID-19 Ag test in persons infected with the B.1.1.7 (alpha) variant of SARS-CoV-2 in comparison with that in persons infected with non-B.1.1.7 variants, also after adjustment for viral load. IMPORTANCE Antigen tests for COVID-19 are widely used for rapid identification of COVID-19 cases, for example, for access to schools, festivals, and travel. There are several FDA- and CE-cleared tests on the market. Their performance has been evaluated mainly on the basis of infections by the classical variant of the causing virus, SARS-CoV-2. This paper provides evidence that the performance of one of the most widely used antigen tests detects significantly fewer cases of COVID-19 by the alpha variant than by the classical variants of SARS-CoV-2. This means that the role of antigen tests needs to be reevaluated in regions where other variants of SARS-CoV-2 predominate.

needs to be referenced 4. In the results section, it is stated that some health workers were tested more than once. How many were these and after how long was the retest done? And were the results obtained by both the Ag and PCR test on retest similar or different? This could indirectly contribute to the negative Ag tests and the positive PCR tests because the period for PCR test detection is generally longer compared to the Ag test. 5. The authors state in the discussion that the mutation S235F could explain the low sensitivity in the antigen test. This needs to be discussed objectively and with more references. One paper suggest that this mutation occurs outside the RNA and protein binding interaction interfaces and a mutation analysis done predicts a high stabilisation effect conferred by this mutation (Singh J. 2021 Structure-Function analyses of new SARS-CoV-2 variants......). This would imply that the mutation has no effect on the Ag test. However, another paper (Ross C. 2021 Epitope specific antibody responses....) found the the S235F rendered epitopes completely incapable of binding antibodies generated against the original virus which argument would support the author's findings.
Reviewer #2 (Comments for the Author): The author wanted to understand the cause of the seemingly reducing sensitivity of the PanBio antigen RDT that coincided with the emergence of the B.1.1.7 variant in Netherlands, by comparing the sensitivity of the antigen RDT between the B.1.1.7 and the non B.1.1.7. RealStar SERS COV-2 RT-PCR was the gold standard. Overall the question asked in this study is important due to the unknown implication of variants on the use of Ag RDT in the rapidly evolving SARS COV-2 pandemic.
Comments for improvement 1.The title refers to two SARS COV-2 variants which is misleading. The author compared a variants with or without N501Y. 2.It is not accurate to define the B.1.1.7 variant by just one mutation. The author did not indicate how many of the 65 samples were collected in January and therefore received a full genome sequencing and if any of the non B1.1.7 and the N501Y mutation. Otherwise, it is important for the author to refer to the variants with N501Y as suspected B.1.1.7. 3.It is also not clear why the author excluded the B.1.135 variant from the analysis Staff Comments:

Preparing Revision Guidelines
To submit your modified manuscript, log onto the eJP submission site at https://spectrum.msubmit.net/cgi-bin/main.plex. Go to Author Tasks and click the appropriate manuscript title to begin the revision process. The information that you entered when you first submitted the paper will be displayed. Please update the information as necessary. Here are a few examples of required updates that authors must address: • Point-by-point responses to the issues raised by the reviewers in a file named "Response to Reviewers," NOT IN YOUR COVER LETTER. • Upload a compare copy of the manuscript (without figures) as a "Marked-Up Manuscript" file. • Each figure must be uploaded as a separate file, and any multipanel figures must be assembled into one file. Please return the manuscript within 60 days; if you cannot complete the modification within this time period, please contact me. If you do not wish to modify the manuscript and prefer to submit it to another journal, please notify me of your decision immediately so that the manuscript may be formally withdrawn from consideration by Microbiology Spectrum.
If you would like to submit an image for consideration as the Featured Image for an issue, please contact Spectrum staff.
If your manuscript is accepted for publication, you will be contacted separately about payment when the proofs are issued; please follow the instructions in that e-mail. Arrangements for payment must be made before your article is published. For a complete list of Publication Fees, including supplemental material costs, please visit our website.
Corresponding authors may join or renew ASM membership to obtain discounts on publication fees. Need to upgrade your membership level? Please contact Customer Service at Service@asmusa.org.
Thank you for submitting your paper to Microbiology Spectrum.

Review comments
Title: Comparison of the performance of the PanBioTM antigen-test in infections with two Variants of SARS-CoV-2.
The author wanted to understand the cause of the seemingly reducing sensitivity of the PanBio antigen RDT that coincided with the emergence of the B.1.1.7 variant in Netherlands, by comparing the sensitivity of the antigen RDT between the B.1.1.7 and the non B.1.1.7. RealStar SERS COV-2 RT-PCR was the gold standard.
Overall the question asked in this study is critically important due to the significant implication on the use of Ag RDT in the rapidly evolving SARS COV-2 variants. Thank you for giving us the opportunity to revise our manuscript Spectrum00884-21 entitled "Comparison of the performance of the PanBio antigen-test in infections with two variants of SARS-CoV-2". We thank the reviewers for their additional and helpful suggestions. We have addressed all comments and revised the manuscript accordingly (see below). We have addressed them and revised the manuscript accordingly. We have submitted a new version of the manuscript which shows individual changes or changes sections in red.
On behalf of all authors of Spectrum00884-21 Marc van Ogtrop, MD