New Study Identifies COVID-19 Point-of-Care Tests That Meet WHO’s “Desirable” Characteristics

Researchers at NSF and Novateur Ventures have identified rapid point-of-care COVID-19 tests that performed well in a study called COVID-19 Point-of-Care Diagnostics That Satisfy Global Target Product Profiles. The research was conducted in December 2020 and published in the peer-reviewed journal Diagnostics in January 2021.

Of the more than 1,100 tests independently assessed in the study (by either the FDA or laboratories providing results to the FIND database), 11 met the World Health Organization’s (WHO) “desirable” target product profile (TPP) criteria. TPPs describe desirable and minimally acceptable profiles for four uses cases:

1. Point-of-care test for suspected COVID-19 cases and their close contacts to diagnose acute SARS-CoV-2 infection in areas where reference assay testing is unavailable, or turnaround times obviate clinical utility
2. Test for diagnosis or confirmation of acute or subacute SARS-CoV-2 infection, suitable for low or high-volume needs
3. Point-of-care test for prior infection with SARS-CoV-2
4. Test for prior infection with SARS-CoV-2 for moderate to high volume needs

The study looked at the first and third use cases, and evaluated the point-of-care diagnostic tests (POCT) on criteria such as:

• Clinical sensitivity/specificity
• The limit of detection
• Time to results

More in-depth criteria for each use case are described in this video from WHO.

The authors of the study performed this analysis to educate potential institutional purchasers of the importance of identifying their use case when selecting point-of-care tests.

“A one-size-fits-all approach to the use of COVID-19 POCT is not feasible in response to the SARS-CoV-2 pandemic. Hence, Target Product Profiles have been developed for specific use cases (such as for diagnosis, confirmation, or for surveillance) and target populations to guide industry efforts and help countries to define their testing strategies,” the study states.

The more than 1,100 tests included 300 COVID-19 diagnostic tests that have obtained U.S. Food and Drug Administration (FDA) Emergency Use Authorization (EUA), and more than 850 tests listed on the Switzerland-based Foundation for Innovative New Diagnostics’ (FIND) database.

Before we dive into the 11 tests that met WHO’s desirable characteristics for use cases one and three, let’s talk about the different types of coronavirus tests: molecular, antibody and antigen.

• Molecular tests detect genetic material from the virus, usually through a nasal or throat swab. A positive result indicates with good probability that you are currently infected.
• Antibody tests detect antibodies, Y-shaped molecules made by the immune response to disable a virus or mark it for destruction. These types of tests are collected by drawing blood and can tell you if you were infected in the past or if you have been vaccinated.
• Antigen tests are the most recent of the three test types used for COVID-19 testing and are usually available as rapid tests. These detect antigens, which are pieces of the virus that the immune system recognizes. These tests can tell you if you are currently infected, but not as effectively as a molecular test.

Ali Ardakani, the managing director at Novateur Ventures and a co-author of the study, said most manufacturers “rushed to develop the COVID tests” without really thinking through the target product profile. You can hear more of what he has to say in this short video.

In the NSF and Novateur Ventures study, five direct antigen/RNA tests for detection of acute infection and six indirect antibody tests for detection of prior infection met the WHO’s TPP criteria:

Direct (Antigen/RNA) POC Tests:

• DetectaChem MobileDetect Bio BCC19 Test (RT‐LAMP)
• Mammoth Biosciences SARS‐CoV‐2 Detectr Test (RT‐LAMP/CRISPR)
• Quidel Sofia‐2 Flu+SARS Antigen Test
• Seasun Biomaterials AQ‐TOP Plus COVID‐19 Rapid Test (RT‐LAMP)
• Shenzhen Bioeasy Biotechnology Bioeasy Diagnostic Kit COVID‐19 Antigen Test

Indirect (Antibody) POC Tests:

• Guangzhou Wondfo Biotech Wondfo SARS‐CoV‐2 Ab Test 1
• Hangzhou Biotest Biotech RightSign COVID‐19 IgG/IgM Rapid Test
• Hangzhou AllTest Biotech AllTest COVID‐19 IgG/IgM Rapid Test 1
• NG Biotech NG IgG/IgM Rapid Test
• Sugentech SGTi‐flex COVID‐19 IgG
• VivaChek Biotech COVID‐19 IgM/IgG Rapid Test

It’s important to note that many tests were developed before the WHO developed the TPP criteria. The WHO’s TPPs are intended to set standards and guidelines for the tests so manufacturers and purchasers can develop and compare tests appropriately.

One of the key takeaways: Researchers hope their work can help communities and health care systems make more informed decisions when choosing rapid COVID-19 tests.

“As communities around the world consider expanding existing COVID-19 testing strategies to include large-scale, rapid point-of-care tests, it’s essential for them to understand which tests work best in different situations,” said study co-author Robyn Meurant, Executive Director of Health Sciences at NSF. “Our previous research found significant variability in performance and features of commercially available point-of-care tests, which makes it difficult to select and procure an appropriate test for a specific use case.”

Meurant added some lessons we can learn from the study:

• The research identified only a few of the many tests available that may fit these different use cases. It is hoped that developers will aim to meet these WHO requirements with the new tests coming to market.
• Test implementers can use the findings of this study as a starting point in deciding what assays they may choose, being aware the performance of new tests that also have been independently assessed must also be considered.

Contact Thomas Frey, APR at media@nsf.org for more information or to get in touch with NSF’s diagnostic experts.