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SARS-CoV-2 Variants are Being Recognized by T Cells

May 18, 2021 10:05:00 AM / by Stacy Matthews Branch, DVM, PhD

AdobeStock_428376842 (1)-1The COVID-19 vaccine uses T cells to recognize the virus, and researchers have found that the CD8+ T cells still recognize the different variants of the virus.

In the United States and abroad, there are reports of the emergence of mutations in SARS-CoV-2 (the virus that causes COVID-19) in human populations. This phenomenon raises concerns regarding whether there is any protection provided by immunity developed to the first virus. To address these concerns, a collaboration of scientists from the National Institute of Allergy and Infectious Diseases (NIAID), Johns Hopkins University School of Medicine, Johns Hopkins Bloomberg School of Public Health, and ImmunoScape conducted a study to examine the blood of people who recovered from COVID-19 before the discovery of SARS-CoV-2 variants.

Previous studies have shown the important role of CD8+ T cells in SARS-CoV-2 immunity. Given this knowledge, the scientists studied whether CD8+ T cells from patients who recovered from COVID-19 caused by the initial virus could recognize three different variants (B.1.1.7, B.1.351, and B.1.1.248). Although mutations are found to exist throughout various parts of the viral genomes of the different variants, they each have the same mutation (N501Y) in the spike protein used by the virus to gain entry into cells.

Results of previous studies show that the variants can still be neutralized by already produced antibodies, but at different degrees depending on the variant. The B.1.1.7 variant exhibits a mild decrease in susceptibility to antibodies from COVID-19 convalescent and post-vaccination plasma. However, the B.1.351 variant exhibits a substantial decrease in susceptibility to antibodies from some convalescent individuals, but it is not clear if the antibodies still provide some level of protection.

The T-cell study results led to the identification of one mutation from the three studied variants, and the mutation overlapped with 52 CD8+ T cell epitopes identified in convalescent individuals of a previous study. Based on the epitope location of the mutation, it is likely that it may not significantly affect recognition by T cell receptors. The researchers determined that SARS-CoV-2-specific CD8+ T-cells recognized all of the studied variants and that beneficial T-cell responses appear to remain unaffected by the mutations. Additional studies with a more significant number of study samples will help to further determine the strength of initial T cell immunity against variants of concern.

T cells are extremely important when developing vaccines, and now that we know they can recognize variants, it will be easier to create future vaccines. If you are looking to invest in cellular products for the advancement of medicine, contact HemaCare today.


T cells recognize recent SARS-CoV-2 variants. (2021). Retrieved 11 May 2021, from

Topics: T Cells, Vaccine Research

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