T-cell Immunity Against COVID-19 and UK Variant in Infected and
Vaccinated Individuals
Abstract
Understanding the composition of human immune responses to SARS-CoV-2
and vaccines is essential for predicting protection from infection and
determining vaccine efficacy. Here, we explored T-cell immune responses
to SARS-CoV-2 and the UK (B.1.1.7) variant of concern (VOC) in infected
and vaccinated individuals. In infected patients, CD4+ T-cells
demonstrated consistent, robust responses against Spike peptides, while
CD8+ T-cells had heterogeneous responses to 5 SARS-CoV-2 proteins. We
found 80% of infected and vaccinated individuals showed positive CD4+
T-cell immunity against SARS-CoV-2. Moreover, CD4+/CD8+ T-cell responses
to SARS-CoV-2 and the United Kingdom (B.1.1.7) variant are robust and
nearly identical in infected and vaccinated individuals. Thus, the UK
variant did not interfere with T-cell recognition and elicited
responses. These observations will be of critical importance in
assessing human immune responses to emerging VOCs.