The T cell receptor repertoire reflects the early dynamics of the immune response to vaccination

Abstract Early ascertainment of the immune response to vaccinations is important. The T cell receptor (TCR) a promising target achieve this, with complete TCR repertoire in PBMCs reflecting cells present an individual. To this end, we developed Tseek, unbiased and accurate method for profiling by sequencing α β chains developing suite tools analysis. We explored both COVID-19 mRNA vaccine (n=9) seasonal inactivated Influenza (n=5) at several time points. Neutralizing antibody titers were also measured covid samples. elicited broad involving multiple expanded clones, whereas narrower fewer clones. Distinct clones responded different points over month, providing temporal details lacking measurements. physical symptoms following administration not indicative TCR/antibody responses while broadly presaged responses. Additionally, akin fingerprint: donors blood samples taken years apart could be identified from repertoire. shows great promise as early sensitive measure adaptive vaccination, which can help improve immunogen selection optimize dosage spacing between doses.