FDA Authorizes Sequencing-Based COVID-19 Diagnostic Test

FDA recently issued an emergency use authorization for a sequencing-based COVID-19 diagnostic test.

The T-Detect COVID Test, developed by Adaptive Biotechnologies, is intended to identify individuals with an adaptive T-cell immune response to SARS-CoV-2, indicating recent or prior infection with COVID-19.

The test is authorized for use by qualified healthcare professionals on samples from individuals who are 15 days or more post-symptom onset. 

Currently, testing with T-Detect COVID Test is limited to laboratories designated by Adaptive Biotechnologies that are certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), FDA explained.

Additionally, the laboratories must meet requirements to perform these high complexity tests.

“Today’s authorization further underscores the FDA’s commitment to innovation in test development,” Jeff Shuren, MD, JD, director of FDA’s Center for Devices and Radiological Health, said in the announcement. 

“The T-Detect COVID Test is a novel technology that assesses the T cell immune response to COVID-19. Information and scientific data that deepen our understanding of SARS-CoV-2 remain important keys to get ahead of this global pandemic,” Shuren continued. 

T-Detect COVID Test analyzes DNA sequences from T-cells to aid in identifying individuals with an adaptive T cell immune response to SARS-CoV-2. A positive test result shows if a patient has recently been infected with the virus, while a negative test result shows that a patient has unlikely been infected. 

FDA noted that negative test results do not preclude acute or current SARS-CoV-2 infection.

Additionally, all results that individuals receive should be used in combination with a clinical examination, patient medical history, and other important findings. 

“People who have been unsure about a prior infection will now have another way to know if they had the virus,” Chad Robins, chief executive officer of Adaptive Biotechnologies, said in a press release following the authorization.  

“The authorization of T-Detect COVID represents a true breakthrough for patients and a pivotal milestone for the diagnostic testing paradigm. We have proven that it is possible to read how T cells detect disease in the blood, and this is just the beginning of a pipeline of tests for many other indications,” Robins continued. 

The emergency use authorization was based on positive results from a clinical trial, which showed that T-Detect COVID elicited sensitivity of 97.1 percent from data of diagnosis using RT-PCR. The test also showed a specificity of 100 percent. 

Researchers concluded that, based on the sensitivity of the test, it has the ability to correctly identify a positive case, while its specificity demonstrates its ability to identify a negative case. 

It is unknown how long the T-cell immune response remains following infection and what level of protection may be provided by the presence of a T-cell immune response.

The T-Detect COVID test will be useful to help determine if an individual previously had COVID-19. This is important for those who may have exhibited symptoms previously or have been exposed but have not tested positive for COVID-19 using another coronavirus test, FDA explained.

At the end of March 2020, FDA Commissioner Stephen M. Hahn, MD, provided an update on the review processes and procedures for the authorization of COVID-19 diagnostic tests.

The update emphasized that FDA will continue to work with test developers during the pandemic to slow and ultimately tackle the virus.

FDA also provided recommendations on evaluating test accuracy for test developers and put together a form for developers to easily share test information to expedite the process of an emergency use authorization.

To respond to the urgent testing needs, FDA also revised the process to allow labs to begin testing prior to FDA review of their validation data.

Since the updates were implemented, FDA has authorized Quest Diagnostics RC COVID-19 + Flu RT-PCR Test, Ellume’s over-the-counter COVID-19 diagnostics test, and the Yale School of Public Health’s SalivaDirect COVID-19 diagnostic test.