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. The T-Detect COVID Test provides a clear positive or negative answer, where a positive result confirms a past immune response to COVID-19 and a negative result confirms no past immune response to COVID-19.
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 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 COVID-19 patients 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

Why study T cells when measuring and monitoring an immune response to vaccines?
As we learn more about the role T cells play in immunity, vaccine developers are recognizing the need to measure the T cell response in addition to the antibody response to their vaccines. The same qualities that make a T cell test ideal for diagnostic purposes also underscore its utility for measuring immune response to vaccines. Adaptive recently launched a T cell monitoring research tool to offer vaccine developers a way to integrate our map of SARS-CoV-2-specific T cells into their vaccine trials.
This is the first molecular T cell monitoring tool for SARS-CoV-2 that accurately, quantitatively, and reproducibly measures the T cell immune response to vaccines and tracks the persistence of that response over time. We are providing data that map those TCRs to SARS-CoV-2 antigens, a capability that may significantly improve the ability to measure the immune response to vaccines in development. Importantly, we can do this from a simple blood sample that does not require any special storage or handling.

Frequently Asked Questions
- T cells are the first responders of the adaptive immune system and activate the antibody response. While antibodies naturally wane and are detectable in the shorter term, T cell responses persist in the blood long after antibody responses wane.1
- The T-Detect COVID Test can detect T cells in your 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 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.
- 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.
In preliminary studies, 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 positive patients, while the serology (antibody) tests had a range of 77-97% detecting of COVID positive patients.1
- In another study, 5+ months after PCR diagnosis, the T-Detect COVID test detected 95% of COVID positive patients, while the serology (antibody) tests had a range of 52-71% in detection of COVID positive patients.2
- In studies, T-Detect COVID Test showed a specificity of >99%.2
- 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.
- 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
- In preliminary studies, 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 positive patients, while the serology (antibody) tests had a range of 77-97% detecting of COVID positive patients.1
- In another study, 5+ months after PCR Diagnosis, the T-Detect COVID test detected 95% of COVID positive patients, while the serology (antibody) tests had a range of 52-71% detecting of COVID positive patients.2
- In studies, T-Detect COVID Test showed a specificity of >99%.2
- 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.
- 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.
- Adaptive Data on File
Researchers interested in using the T-Detect COVID Test for their projects, studies or trials can contact us here.
- 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-MAPTM 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 here.
Please contact COVID19ImmuneResponse@adaptivebiotech.com with a brief description of your project or study, Adaptive will respond to discuss next steps.
In vitro diagnostic for prescription use only. This test has not been cleared or approved by the FDA. The T-Detect COVID Assay is available for use as a CLIA-validated laboratory developed test (LDT). T-Detect COVID is not indicated for use in patients under age 18.
immunoSEQ technology is research use only. Not for use in diagnostic procedures.
For Patients
The T-Detect COVID Test can detect past infection months after exposure.
For Physicians
The T-Detect COVID Test may capture COVID-19 infections missed by serology tests.
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.