Pressurised COVID-19 testing systems catalyse the search for new solutions

In July, I wrote a short update blog on the COVID-19 diagnostic situation. At the time, governments around the world seemed to be operating relatively stable testing systems, capable of turning around reliable results in a timely manner. However, as schools and workplaces have begun to reopen, the demand for testing has started to increase, placing many systems under considerable pressure. In the UK, for example, we are now seeing sporadic reports of shortages of tests, individuals being turned away from drive-in facilities and a slowing of the result turnaround time. This situation is now being seen, to a lesser or greater extent, in many countries around the world.¹

As we have discussed previously, having access to reliable and rapid testing technology is an absolutely critical component of tackling any pandemic. Molecular testing currently dominates our response to COVID-19 because it is highly accurate. However, this type of lab-based testing is a complicated process which can quickly stall at times of elevated demand; the samples generally need to be 1) collected via a throat swab by a trained technician at an appropriate location, 2) sent away to a specialist facility for analysis and 3) returned the individual in a timely manner. Each of these three components can represent a ‘pinch-point’ in times of high demand, and this seems to be what many governments are beginning to experience at the time of writing. This has really put the current system under the microscope, and has seen the search for alternative testing methods intensify.

In July, I introduced the concept of rapid antigen testing. At that time, the US Food and Drug Administration (FDA) had granted Emergency Use Authorisation (EUA) to just two rapid antigen tests from major US diagnostic firms. While these tests undoubtedly offer a quicker alternative to molecular testing, they both still require a lab facility and specialist instrumentation to perform. Since July, two further antigen tests have been approved, one of which being a visually-read technology from healthcare company Abbott.

Abbott’s BinaxNOW COVID-19 Ag CARD test is a $5, 15-minute lateral flow test based on established gold nanoparticle technology.² The test has high sensitivity (97%) and specificity (98%) derived from clinical studies performed at different sites, and the company has established significant production capacity with a view to shipping tens of millions of tests in September and ramping up manufacturing to 50 million tests a month in October. Indeed, it has been reported that the FDA may soon authorise additional antigen tests for use, potentially bringing hundreds of millions of tests onto the market.³

Abbott’s test has also been named alongside a similar gold-based antigen test developed by SD Biosensor as part of the Bill and Melinda Gates Foundation’s efforts to get quality tests into the hands of people in Low and Middle-Income Countries (LMICs). This programme, supported by FIND Diagnostics, The Global Fund and the World Health Organisation, is committing $50m to purchase the tests for distribution in LMICs around the world.⁴

There are, of course, challenges to developing these types of technologies at such speed. Accuracy remains a concern; there have been a number of instances of both antigen and antibody tests not performing to the level claimed by the manufacturer so regulatory bodies are now rightly conservative in approving such technologies. Logistics are also a major issue; ramping up production to tens or hundreds of millions of tests in months requires considerable resources and well-established and robust supply chains.

However, progress continues being made at pace and the launch of Abbott’s visually-read test and the Bill and Melinda Gates Foundation commitment to making such tests available in LMICs proves the ongoing importance of gold in the fight against COVID-19. Check out our animation for more information on how these types of tests work, and why they are so important:
 

Footnotes

¹ For example, see https://www.nytimes.com/2020/08/04/us/virus-testing-delays.html

² See the Abbott press release and accompanying website here: https://www.abbott.com/corpnewsroom/product-and-innovation/upping-the-ante-on-COVID-19-antigen-testing.html and here: https://www.abbott.com/BinaxNOW-Test-NAVICA-App.html

³ https://uk.reuters.com/article/us-health-coronavirus-usa-testing/us-plans-for-hundreds-of-millions-of-cheap-fast-covid-19-tests-idUKKBN2681ME

⁴ See the FIND press release here: https://www.finddx.org/newsroom/pr-28sep20/