# Study published in Cell: Long term immunity likely even after antibody levels fade **URL:** \ **Category:** The Quarantine Zone\ **Tags:** covid-quarantine\ **Created:** [August 19, 2020, 3:21am UTC](https://boards.straightdope.com/t/study-published-in-cell-long-term-immunity-likely-even-after-antibody-levels-fade/918464 "2020-08-19T03:21:24Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 19, 2020, 9:54am UTC](https://boards.straightdope.com/t/study-published-in-cell-long-term-immunity-likely-even-after-antibody-levels-fade/918464/3 "2020-08-19T09:54:26Z")
The short answer is no, we will not have a high-throughput routine clinical test for cell-mediated immunity like the antibody test. (Disclaimer - I’m not a expert in this specific field, but I have some knowledge of it.) Antibodies recognize viral proteins in their natural state, and antibodies are small. So the antibody test immobilizes viral protein antigen on a surface, then any antibodies in the patient sample that are specific to the viral protein antigen will stick to that surface where they can be detected. (Google ELISA test for more detail) Unlike antibodies, T-cell receptors recognize processed segments of viral protein in complex with MHC molecules, for interesting reasons that I talked about here: > [@Any new news on why this is severe/lethal to some, and not others?](https://boards.straightdope.com/t/any-new-news-on-why-this-is-severe-lethal-to-some-and-not-others/852273/9): > > A prominent innate source of variation in immune response is the Major Histocompatibility Complex, aka Human Leukocyte Antigen - google MHC haplotype or HLA haplotype. MHC molecules sit on the surface of certain cells that process any proteins that they find and present them to the immune system for inspection. The MHC is the most genetically diverse region of the human genome, and it’s subject to active natural selection for diversity: it’s often an advantage to have different MHC alleles t… So, there are two challenges. First, the thing that T-cell receptors recognize is significantly more complex than just a viral protein in its raw state, so you have to make that, and you also have to label it with a fluorescent tag because of the second problem… You’re looking for cells, which are much larger than antibodies and cannot be immobilized on a surface in the same way. I’m not aware of any T-cell assay that does not involve flow cytometry, a much more complex experimental technique. The fact that these experimental techniques are more difficult is the reason that it’s taken time to produce this research on cell-mediated immunity. --- _[View the full topic](https://boards.straightdope.com/t/study-published-in-cell-long-term-immunity-likely-even-after-antibody-levels-fade/918464)._