On Mar. 5, 2020, Adaptive Biotechnologies announced that the U.S. Food and Drug Administration (FDA) had issued an Emergency Use Authorization (EUA) for T-Detect COVID to confirm recent or prior COVID-19 infection. This first-in-class T cell- based test was the first indication resulting from Adaptive’s TCR-Antigen Map collaboration with Microsoft.

EUA was based on a clinical validation study showing that T-Detect COVID demonstrated sensitivity of 97.1% from date of diagnosis using RT-PCR. Sensitivity is the ability of the test to correctly identify a positive case (true positive). T-Detect COVID also showed a specificity of 100%. Specificity is the ability of the test to identify a negative case (true negative).

The FDA provides an EUA for medical products to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions when there are no adequate, approved, and available alternatives.

T cells are the adaptive immune system’s first responders to detect any virus. They quickly multiply and circulate in the blood to attack the virus, often before symptoms appear. Among many other jobs, T cells also recruit B cells to produce antibodies after about a week or two to potentially provide immunity against future infection. T cells contain a treasure trove of information that could provide one consistent and trackable measure of the immune response to COVID-19 from initial exposure through viral clearance.

T cells can “remember” prior infections and kill pathogens if they reappear. Research shows that antibodies to SARS-CoV-2 decline over time. T cells hold important clues to immunity and correlates of protection and need to be studied to assess how long patients remain resistant to reinfection. Given T cells circulate freely in the blood, they are an easy and thus a desirable target for assessing SARS-CoV-2 exposure and potentially immunity.

T-Detect^™ is a highly sensitive and specific diagnostic test under development for multiple diseases, translating the natural diagnostic capability of T cells into clinical practice. In 2018, Adaptive and Microsoft partnered to build a map of the immune system called the TCR-Antigen Map. This approach uses immunosequencing, proprietary computational modeling, and machine learning to map T-cell receptor sequences to disease-associated antigens for infectious diseases, autoimmune disorders and cancer.

From a simple blood draw, T-Detect will leverage the map to provide an immunostatus for an individual, enabling early disease diagnosis, disease monitoring, and critical insights into immunity. T-Detect COVID is the first clinical test launched from this collaboration and the first commercially available T-cell test designed to detect recent or prior SARS-CoV-2 infections. T-Detect COVID is an EUA authorized test that is available for prescription use only.