The T-cell response has not as yet been measured commercially in those previously infected or those vaccinated against SARS-CoV-2 infection.
Lowe and others in their article published in Science, 18th June 2021, suggest that a better understanding of the CD4 plus T-cell response to SARS-CoV-2 is crucial to the design of effective next generation vaccines.
In their paper, they defined an estimated the CD4 T-cell repertoire of convalescent COVID-19 patients.
After sorting out the various CD4 plus T cell subsets, they generated numerous T-cell clones that reacted to the SARS-CoV-2 spike protein.
In around a third of all clones and almost all individuals, the T-cells recognised a small conserved immunodominant region within the spike protein receptor binding domain the RBD.
The researchers isolated T-cell clones that broadly reacted with the spike protein of other coronaviruses, providing evidence for the recall of pre-existing, cross-reacted memory T-cells after SARS-CoV-2 infection.
They characterised 2943 S reactive T-cell clones from 34 individuals and found that the RBD was highly immunogenic and that 33% of RBD reactive clones and 94% of individuals recognised a conserved immunodominant region comprising nested human leukocyte antigens.
Using pre and post COVID-19 samples and S proteins from endemic coronaviruses they identified cross reactive T cells targeting multiple S protein sites.
They argue these immunodominant and cross-reactive epitopes can inform vaccination strategies to counteract emerging SARS-CoV-2 variants.
The London General Practice provides all forms of COVID testing.
This includes all aspects of travel, including fit to fly, lateral antigen, rapid antigen tests, day two, five and eight tests, day five test for release.
The London General Practice is also able to now offer a T-cell test, which helps to elucidate whether there has been a T-cell humoral response to either vaccination or infection.
Dr Paul Ettlinger
Founder, The London General Practice