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It’s hard to believe that it’s been more than 2 years since the World Health Organization (WHO) declared COVID-19 a global pandemic on March 11, 2020. At that time, the scientific world and public health communities all came together to identify the cause of this outbreak, to understand the type of “virus” infecting people and identify the infectious “disease” causing so many deaths around the world.

Fast forward to the first five months of 2022, where we now find ourselves removing COVID-19 restrictions at the same time cases are rising in the U.S. due to the “newest” Omicron subvariant BA.2.12 and BA2.12.11 wave.

How many SARs-CoV-2 variants of concern (VOC) are there?

What We Know about Omicron

It’s amazing how much we have learned about COVID-19 during these past two years of the pandemic. SARS-CoV-2, like other RNA viruses2, is prone to genetic evolution while adapting to their new human hosts with the development of mutations over time, resulting in the emergence of multiple variants that may have different characteristics compared to its ancestral strains. Viruses mutate all the time, but only some mutations affect their ability to spread or evade prior immunity from vaccination or infection, or the severity of disease they cause.

The evolution of the SARS-CoV-2 virus over the course of the COVID-19 pandemic has resulted in the emergence of five variants of concern (VOC)3—Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1) Delta (B.1.617.2) and Omicron (B.1.1.529): —to date. In late December 2021, Omicron overtook Delta as the dominant variant in the U.S, and by the end of April 2022, surpassed the original Omicron strain to become the predominant COVID-19 variant in the U.S.

The Omicron variant, officially known as B.1.1.529, of SARS-CoV-2 has three main subvariants in its lineage4: BA.1, BA.2 and BA.3. Omicron has also undergone 50 mutations when compared to its previous variants of SARS-CoV-2: Alpha, Beta, Gamma, and Delta, and it is found to be the most prominent and distinct VOC as the spike protein of Omicron has 26 amino acid mutations from the millions of SARS-CoV-2 genomes.5

The BA.1 subvariant has over 30 mutations6 in the spike protein that helps it enter cells. Spike protein mutations7 are of high concern to scientists and public health officials because they affect how infectious a particular variant is and whether it is able to escape the protective antibodies that the body produces after vaccination or a prior COVID-19 infection.

BA.2 or the “stealth variant” has eight unique mutations that make it more transmissible than the original Omicron variant, but lacks the 13 mutations that BA.1 has. BA.2 does, however, share around 30 mutations with BA.1.8

XE: A hybrid variant of Omicron

The XE sub-variant is a recombinant hybrid strain of Omicron BA.1 and BA.2 that contains mutations found in both variants. A recombinant occurs when two or more variants of the virus infects the same cell, in the same person, at the same time, and combines their genetic material.9 Omicron XE appears to be more transmissible than Omicron BA.2, which appears to be more transmissible than Omicron BA.1.

Is Omicron more transmissible than previous variants?

According to the CDC, the Omicron variant spreads more easily than the original SARS-CoV-2 virus and the Delta variant. BA.2 shares many genetic similarities with its BA.1 subvariant, but BA.2 is between 30 percent and 50 percent more contagious than BA.1, appears to spread even faster that BA.1, but it does not appear to cause more severe disease than BA.1.10

A continued need for POC COVID-19 molecular testing

While the COVID-19 virus is still with us and continues to evolve, we should expect to see new variants emerge and disappear as they compete against each other and other circulating viruses. We should continue to protect ourselves and use the tools that we have at our disposal to respond to this ongoing pandemic.

COVID-19 testing is critical and remains important to help keep life moving forward, as new variants may continue to emerge.13 While there are many different types of tests that have emergency use authorization (EUA) in the United States, including molecular diagnostics/nucleic acid amplification tests (NAAT), antigen tests, and serological tests, molecular testing remains the gold standard for identifying SARS-CoV-2 infection.11

“Current diagnostic tests for the SARS-CoV-2 pandemic use nucleic acid, antibody and protein-based detections, but viral nucleic acid detection by RT–PCR remains the gold standard.”

–Kevadiya, et al.12

Talis One™: The next big thing in COVID-19 molecular testing

At Talis, we believe that accurate POC molecular tests that can provide results in minutes instead of hours are needed to meet the need for fast, accurate testing. But not all POC NAATs deliver the same accuracy and sensitivity that central lab NAATs deliver12, which is why we developed the Talis One COVID-19 Test System.

Designed to deliver central lab quality NAAT results quickly and in a variety of care environments, the Talis One COVID-19 Test System is the answer for rapid, POC COVID-19 molecular testing needs. Unlike other POC COVID-19 tests that may not be as sensitive, the Talis One COVID-19 Test System achieves lab-quality detection thanks to our proprietary on-cartridge sample extraction step and other patented technologies that give our assay a limit of detection (LOD) of 500 copies/mL.

Learn more about our Talis One COVID-19 Test System

Meet the Talis One

References

  1. CDC Tracker Interpretive Summary for April 22, 2022. Unpacking Variants. J Phys Chem Lett Omicron BA.2 (B.1.1.529.2): High Potential for Becoming the Next Dominant Variant 2022 May 5;13(17):3840-3849. Epub 2022 Apr 25.
  2. National Library of Medicine – Emerging Variants of SARS-CoV-2 And Novel Therapeutics Against Coronavirus (COVID-19) 2022 Feb 6. Aleem A, Akbar Samad AB, Slenker AK.
  3. National Library of Medicine – Emerging Variants of SARS-CoV-2 And Novel Therapeutics Against Coronavirus (COVID-19) 2022 Feb 6. Aleem A, Akbar Samad AB, Slenker AK.
  4. CDC-COVID-19 SARS-CoV-2 Variant Classifications and Definitions
  5. Eur Phys J Plus. 2022; 137(1): 100. – Published online 2022 Jan 10 doi: 10.1140/epjp/s13360-021-02321-y.
  6. Acta Pharmacologica Sinica- Review Article. Published: 03 August 2020. Structural and functional properties of SARS-CoV-2 spike protein: potential antivirus drug development for COVID-19. Huang, Y., Yang, C., Xu, Xf. et al.
  7. Acta Pharmacologica Sinica volume 41, pages 1141–1149 (2020). Structural and functional properties of SARS-CoV-2 spike protein: potential antivirus drug development for COVID-19. Huang, Y., Yang, C., Xu, Xf. et al.
  8. N Engl J Med 2022; 386:1579-1580. Neutralization of the SARS-CoV-2 Omicron BA.1 and BA.2 Variants.
  9. UK SARS-CoV-2 variants of concern and variants under investigation in England. Technical briefing 40Security. What is Omicron XE Variant and is there cause for concern?
  10. MedRxiv and BioRxiv. Occurrence and significance of Omicron BA.1 infection followed by BA.2 reinfection. Posted February 22, 2022.
  11. The Infectious Diseases Society of America Guidelines on the Diagnosis of COVID-19: Molecular Diagnostic Testing. Published. 2021 Jan 22. doi:10.1093/cid/ciab048. Hanson KE, Caliendo AM, Arias CA, et al.
  12. Diagnostics for SARS-CoV-2 infections. Nat Mater. Published 2021;20(5):593-605. doi:10.1038/s41563-020-00906-z. Kevadiya BD, Machhi J, Herskovitz J, et al.
  13. COVID-19 Testing: What You Need to Know – Updated May 3, 2022.
     

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    TALIS BIOMEDICAL

    The GenBody COVID-19 Ag Test and the Talis One COVID-19 Test System are for use under Emergency Use Authorization (EUA) only. For In Vitro Diagnostic (IVD) use. For prescription use only. Talis is an authorized distributor of the GenBody COVID-19 Ag test.

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    *Additional testing solutions are currently in development and not available for sale.