T cell responses arise earlier than antibodies and last through clearance into convalescence.1
The T-Detect COVID test is the first clinical test that detects T cells to confirm recent or past SARS-CoV-2 infections. T-Detect COVID test results are a binary positive/negative result. A positive result means there was a recent or past exposure to SARS-CoV-2, the virus that causes COVID-19. A negative result indicates that past exposure to SARS-CoV-2 probably did not occur.
Much of what we are learning about T cells is consistent with what we see in the immune response to other viruses, but the combination of global scientific focus and the number of people infected with the virus in such a short period of time has led to an understanding of the variability of individual responses on a greater scale. In the setting of COVID-19, we are seeing:
T cells persist longer than antibodies
* Based on prior research on coronavirus T cell response 2,3
- T cell responses arise earlier than antibodies and last through clearance into convalescence.1
- T cells play a critical role in supporting the development of antibodies by B cells and can serve as the first signs of an immune response to SARS-CoV-2 infection.2
- The majority of individuals with COVID-19 generate a T cell response comprised of both CD8+ T cells, or “killer” T cells which destroy virus-infected cells, and CD4+ “helper” T cells, which help other immune cells, including B cells which produce antibodies.3
- CD8+ & CD4+ T cells were observed in convalescent patients with mild and severe COVID-19 disease.4
Frequently asked questions
T cells are the first responders of the adaptive immune system and activate the antibody response. While antibodies to SARS-CoV-2 (the virus that causes COVID-19 infection) naturally wane and are detectable in the shorter term, T cell responses can persist in the blood long after antibody responses wane.1,2,4
The T-Detect COVID test can detect T cells in a blood sample that can remain for up to several months after symptoms appear.1,2,3
- Zuo J, et al. Robust SARS-CoV-2-specific T-cell immunity is maintained at six months following primary infection. bioRxiv. 2020.
- Adaptive data on file.
- Ng, O, et al. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection. Vaccine. 2016.
- Dalai, S, et al. Clinical Validation of a Novel T-Cell Receptor Sequencing Assay for Identification of Recent or Prior SARS-CoV-2 Infection. medRxiv. 2020.
The T-Detect COVID test measures a T cell response against SARS-CoV-2, the virus that causes COVID-19, present in a subject’s blood. The test utilizes Adaptive’s immunoSEQ Technology to sequence T-cell receptors (TCRs) from a blood sample and identifies TCRs that Adaptive has mapped for recognition of SARS-CoV-2 antigens. The test identifies subjects who have evidence of a cellular immune response against SARS-CoV-2.
When the T-Detect COVID test was compared with serology testing:
- In one study, ~2 months after PCR diagnosis, the T-Detect COVID test detected 97% of COVID-19 positive patients, while the serology (antibody) test had a range of 77-99% detection of COVID-19 positive patients.1
- In another study, 5+ months after PCR diagnosis, the T-Detect COVID test detected 95% of COVID-19 positive patients, while the serology (antibody) test had a range of 52-71% in detection of COVID-19 positive patients.2
- In studies, the T-Detect COVID test showed a specificity of >99%.1
- Dalai, S, et al. Clinical Validation of a Novel T-cell Receptor Sequencing Assay for Identification of Recent or Prior SARS-CoV-2 Infection. medRxiv. 2021.
- Adaptive data on file.
Individuals with mild or asymptomatic COVID-19 may not mount a detectable antibody response and may instead resolve infection through a cellular immune response.1,2
Traditional antibody (serology) tests measure IgM, IgG, and/or neutralizing antibodies to SARS-CoV-2 (the humoral component of the adaptive immune response). The T-Detect COVID test instead measures the cellular adaptive immune response to SARS-CoV-2 through T cell receptor sequencing.1,3
When the T-Detect COVID test was compared with serology testing:
- In one study, 15 or more days after symptom onset with PCR-diagnosed COVID-19, the T-Detect COVID test identified 94.5% of patients, while leading serology (antibody) tests had a test range from 88.0-90.4%.3
- In another study, 5+ months after PCR diagnosis, the T-Detect COVID test detected 95% of COVID positive patients, while the serology (antibody) test had a range of 52-71% in detection of COVID-19 positive patients.4
- In studies, the T-Detect COVID test showed a specificity of >99%.3
- Long Q, et al. Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections. Nat Med. 2020.
- Shields AM, et al. SARS-CoV-2 seroconversion in health care workers. medRxiv. 2020.
- Dalai, S, et al. Clinical Validation of a Novel T-cell Receptor Sequencing Assay for Identification of Recent or Prior SARS-CoV-2 Infection. medRxiv. 2021.
- Adaptive data on file.
The immunoSEQ® Assays sequence the full repertoire in your samples and you will receive the immune receptor sequencing data on your samples where you can apply the immunoSEQ® T-MAP™ COVID Tool to identify SARS-CoV-2-specific TCRs in your samples.
The T-Detect COVID test should be applied where a positive/negative result will suffice for your research.
If you’d like to learn more about how you can use immunoSEQ or T-Detect in your research or clinical trials, please contact us.
Contact COVID19research@adaptivebiotech.com with a brief description of your project or study and Adaptive will respond to discuss next steps.
This test has not been FDA cleared or approved but has been authorized for emergency use by FDA under an EUA.
Testing of venous whole blood using K2 EDTA specimens is limited to laboratories designated by Adaptive Biotechnologies Corporation that are certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, and meets the requirements to perform high complexity tests as described in the T-Detect COVID Test Standard Operating Procedure that was reviewed by the FDA under this EUA.
This test has been authorized only for detecting and identifying the presence of an adaptive T-cell immune response to SARS-CoV-2, not for any other viruses or pathogens.
The emergency use of this test is only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of in vitro diagnostics for detection and/or diagnosis of COVID-19 under Section 564(b)(1) of the Federal Food, Drug and Cosmetic Act, 21 U.S.C. § 360bbb3(b)(1), unless the declaration is terminated or authorization is revoked sooner.
T-Detect™ COVID is not indicated for use in patients under age 18.
For Patients
The T-Detect COVID test can detect past COVID-19 infections for up to several months.
For Physicians
The T-Detect COVID test can capture past COVID-19 infections that may be missed by serology testing.
For Employers
The T-Detect COVID test can help your employees get the answers they need.
References
- Zuo J, et al. Robust SARS-CoV-2-specific T-cell immunity is maintained at 6 months following primary infection. bioRxiv. 2020.
- Channappanavar R, et al. Virus-specific memory CD8 T cells provide substantial protection from lethal Severe Acute Respiratory Syndrome Coronavirus infection. J Virol. 2014;88(19):11034-11044.
- Ng O, et al. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection. Vaccine. 2016;34(17):2008-2014.
- Gittelman RM, et al. Diagnosis and tracking of past SARS-CoV-2 infection in a large study of Vo’, Italy through T-cell receptor sequencing. medRxiv. 2020.